U.S. patent application number 14/202018 was filed with the patent office on 2014-09-18 for apparatus and method for controlling a locomotive consist.
This patent application is currently assigned to Bright Energy Storage Technologies, LLP. The applicant listed for this patent is Bright Energy Storage Technologies, LLP. Invention is credited to Scott Raymond Frazier, Karl Ginter, Jeffrey Orion Pritchard, Kevin Pykkonen.
Application Number | 20140263861 14/202018 |
Document ID | / |
Family ID | 51523298 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140263861 |
Kind Code |
A1 |
Pritchard; Jeffrey Orion ;
et al. |
September 18, 2014 |
APPARATUS AND METHOD FOR CONTROLLING A LOCOMOTIVE CONSIST
Abstract
A locomotive assembly including a legacy locomotive controller
and an intercept locomotive controller and a method of controlling
a locomotive are disclosed. The locomotive assembly includes a
power bus, a locomotive, and an intercept locomotive controller.
The locomotive includes a primary power unit coupled to the power
bus and a legacy locomotive controller programmed to transmit a
control command to the primary power unit. The intercept locomotive
controller is electrically coupled between the locomotive
controller and the primary power unit and is programmed to
intercept an initial locomotive control signal transmitted from the
legacy locomotive controller to the primary power unit indicating
an amount of locomotive power, modify the initial locomotive
control signal, and transmit the modified control signal to the
primary power unit.
Inventors: |
Pritchard; Jeffrey Orion;
(Oakland, CA) ; Pykkonen; Kevin; (Boulder, CO)
; Ginter; Karl; (Beltsville, MD) ; Frazier; Scott
Raymond; (Morrison, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bright Energy Storage Technologies, LLP |
Arvada |
CO |
US |
|
|
Assignee: |
Bright Energy Storage Technologies,
LLP
Arvada
CO
|
Family ID: |
51523298 |
Appl. No.: |
14/202018 |
Filed: |
March 10, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61799474 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
246/187R |
Current CPC
Class: |
B60L 3/08 20130101; B61C
17/12 20130101; Y02T 30/00 20130101; B61L 15/0081 20130101; B61L
3/006 20130101; B60L 50/10 20190201; Y02T 30/10 20130101 |
Class at
Publication: |
246/187.R |
International
Class: |
B61C 17/12 20060101
B61C017/12 |
Claims
1. A locomotive assembly comprising: a power bus; a locomotive
comprising: a primary power unit coupled to the power bus; and a
legacy locomotive controller programmed to transmit control signals
to the primary power unit; and an intercept locomotive controller
programmed to: intercept an initial locomotive control signal
transmitted from the legacy locomotive controller to the primary
power unit indicating an amount of locomotive power; modify the
initial locomotive control signal; and transmit the modified
control signal to the primary power unit; and wherein the intercept
locomotive controller is electrically coupled between the
locomotive controller and the primary power unit.
2. The locomotive assembly of claim 1 wherein the initial
locomotive control signal comprises an alternator excitation of the
primary power unit.
3. The locomotive assembly of claim 2 wherein the initial
locomotive control signal comprises a pulse generated by a silicon
controlled rectifier (SCR).
4. The locomotive assembly of claim 2 wherein the initial
locomotive control signal comprises a pulse-width-modulated (PWM)
signal.
5. The locomotive assembly of claim 1 further comprising an
auxiliary power unit comprising: an auxiliary power source coupled
to the power bus; and an auxiliary controller electrically coupled
to auxiliary power source.
6. The locomotive assembly of claim 5 wherein the intercept
locomotive controller is further programmed to allocate a power
generation request between auxiliary power unit and the primary
power source; and wherein the primary power source is configured to
respond to the power generation request at a first frequency that
is higher than a second frequency with which the auxiliary power
source responds to the power generation request.
7. The locomotive assembly of claim 6 wherein the auxiliary power
source is configured to respond to the power generation request at
a third frequency, higher than the second frequency, during a
locomotive knockdown event.
8. The locomotive assembly of claim 5 wherein the intercept
locomotive controller is further programmed to: identify operating
parameters of the auxiliary power unit; allocate a first portion of
the desired amount of locomotive power to the auxiliary power unit
based on the identified operating parameters of the auxiliary power
unit; allocate a remaining portion of the desired amount of
locomotive power to the primary power unit; and modify the initial
locomotive control signal to control the primary power unit to
generate the remaining portion of the desired amount of locomotive
power.
9. The locomotive assembly of claim 8 wherein the intercept
locomotive controller is further programmed to allocate all of the
desired amount of locomotive power to the auxiliary power unit
based on the identified operating parameters of the auxiliary power
unit.
10. The locomotive assembly of claim 8 wherein the intercept
locomotive controller is further programmed to allocate the first
portion of the desired amount of locomotive power and the remaining
portion of the desired amount of locomotive power based on a
comparison of operating costs of the auxiliary power unit and
operating costs of the primary power unit.
11. The locomotive assembly of claim 8 wherein the identified
operating parameters of the auxiliary power unit comprise at least
one of an equipment configuration of the auxiliary power unit,
performance characteristics of the auxiliary power unit,
operational history data of the auxiliary power unit, and a current
status of the auxiliary power unit.
12. The locomotive assembly of claim 1 further comprising a sensor
system electrically coupled to the legacy locomotive controller;
and wherein the intercept locomotive controller is further
programmed to: intercept a sensor signal transmitted from the
sensor system to the legacy locomotive controller; modify the
sensor signal; and transmit the modified sensor signal to the
legacy locomotive controller.
13. The locomotive assembly of claim 12 wherein the sensor system
comprises at least one of an RPM sensor coupled to the primary
power unit, an output power sensor coupled to the primary power
unit, and a bus power sensor.
14. The locomotive assembly of claim 1 further comprising: a
traction motor electrically coupled to the primary power unit; and
a traction blower positioned adjacent the fraction motor.
15. The locomotive assembly of claim 14 wherein the intercept
locomotive controller is further programmed to: intercept a
traction blower command signal transmitted from the primary
controller to the traction blower; modify the traction blower
command signal; and transmit the modified traction blower command
signal to the traction blower.
16. The locomotive assembly of claim 15 wherein the modified
traction blower command signal defines an operation setting that
causes the fraction blower to operate at a setting that prevents
the traction motor from overheating.
17. The locomotive assembly of claim 14 wherein the intercept
locomotive controller is further programmed to: define a traction
blower command signal based on the modified command signal; and
transmit the modified traction blower command signal to the
traction blower.
18. The locomotive assembly of claim 14 wherein the intercept
locomotive controller is further programmed to modify the traction
blower command signal to match a fraction blower operation setting
corresponding to the initial locomotive control signal.
19. The locomotive assembly of claim 14 wherein the intercept
locomotive controller is further programmed to: intercept a
traction motor control signal transmitted from the legacy
locomotive controller to the traction motor; modify the traction
motor control signal to match an traction motor operation setting
corresponding to the initial locomotive control signal; and
transmit the modified traction motor control signal to the fraction
motor.
20. A method of controlling a locomotive comprising: relaying an
initial locomotive control signal from a legacy locomotive
controller designed to control at least one power source on the
locomotive to an intercept locomotive controller, the initial
locomotive control signal comprising an encoded request for a
locomotive power setting; determining a power output corresponding
to the locomotive power setting; allocating the power output
between the at least one power source on the locomotive and an
auxiliary power source; transmitting a modified locomotive control
signal to the at least one power source on the locomotive based on
the power output allocation, the modified locomotive control signal
different from the initial locomotive control signal; and
transmitting an auxiliary command signal to the auxiliary power
source based on the power output allocation.
21. The method of controlling a locomotive of claim 20 further
comprising: identifying an operating characteristic of the
auxiliary power source; and defining the power output allocation
based on the operating characteristic.
22. The method of controlling a locomotive of claim 20 further
comprising: relaying signals from at least one sensor on the
locomotive to the intercept locomotive controller; generating a
modified sensor value different than the received sensor value; and
sending the modified sensor value to the locomotive controller.
23. The method of controlling a locomotive of claim 22 further
comprising: intercepting an initial blower motor setting
transmitted from the legacy locomotive controller to a traction
blower motor; determining a traction blower motor setting based on
the relayed signals from the at least one sensor on the locomotive;
and controlling the traction blower motor according to the
determined traction blower motor setting, wherein the determined
traction blower motor setting deviates from the initial blower
motor setting.
24. The method of claim 20 further comprising: controlling the at
least one power source on the locomotive according to the modified
locomotive control signal; controlling the auxiliary power source
according to the auxiliary command signal; and operating at least
one of a traction motor and a blower motor at a control setting
consistent with the initial locomotive control signal.
25. A computer readable storage medium having stored thereon a
computer program comprising instructions which, when executed by at
least one processor, cause the at least one processor to: receive
an initial locomotive power setting command from a locomotive
controller, the initial locomotive power setting command indicating
a desired tractive power; modify the initial locomotive power
setting command; transmit the modified locomotive power setting
command to a locomotive power source; receive a sensor signal
corresponding to the modified locomotive power setting command;
modify the sensor signal to match an expected sensor signal for the
initial locomotive power setting command; and transmit the expected
sensor signal to the locomotive controller.
26. The computer readable storage medium having stored thereon a
computer program of claim 25 wherein the instructions further cause
the computer to: allocate a first portion of the desired tractive
power to the locomotive power source; allocate a second portion of
the desired tractive power to an auxiliary power source; modify the
initial locomotive power setting command to generate a locomotive
command to control the locomotive power source to output the first
portion of the desired tractive power; and generate an auxiliary
command to control the auxiliary power source to output the second
portion of the desired tractive power.
27. The computer readable storage medium having stored thereon a
computer program of claim 26 wherein the instructions further cause
the computer to: receive a sensor signal from at least one of the
locomotive power source and the auxiliary power source; calculate a
modified sensor signal, different from the received sensor signal;
and transmit the modified sensor signal to the locomotive
controller.
28. The computer readable storage medium having stored thereon a
computer program of claim 26 wherein the instructions further cause
the computer to: compare operating costs of the at least one power
source on the locomotive and the auxiliary power source; and
allocate the first and second portions of the desired tractive
power based on the comparison of operating costs.
29. The computer readable storage medium having stored thereon a
computer program of claim 25 wherein the instructions further cause
the computer to: generate a blower motor command consistent with
the initial locomotive power setting command; and control a
locomotive blower motor according to the blower motor command.
30. The computer readable storage medium having stored thereon a
computer program of claim 25 wherein the instructions further cause
the computer to: generate a traction motor command consistent with
the initial locomotive power setting command; and control a
locomotive traction motor according to the traction motor command.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present invention is a continuation of and claims
priority to U.S. Provisional Patent Application Ser. No.
61/799,474, filed Mar. 15, 2013, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] A locomotive consist is the arrangement of locomotives,
slugs, and power tenders which are coupled together to provide
motive power to a train. In one known arrangement, multiple
independent locomotives are linked together using multiple-unit
("MU") controls and operated as a single unit. Locomotives
traditionally used in MU arrangements are powered by
diesel-electric power sources, where a diesel engine drives a
generator to produce electric power. The electricity produced by
these engine-generator sets is in turn used to power one or more
electric traction motors. The traction motors turn the drive wheels
of the locomotive.
[0003] The locomotive controllers provided on traditional
locomotives, referred to herein as "legacy locomotive controllers",
recognize and control fixed engine-generator combination(s)
installed on the locomotive chassis. This arrangement of
locomotives has an independent legacy locomotive controller for
each locomotive chassis, and shares throttle setting (an input to a
locomotive controller), brake settings, and fault indications,
which are communicated using a combination electrical and pneumatic
connection. Each legacy locomotive controller manages a static,
predefined arrangement of one or more engine/generator sets that
provide power to the bus, and the generation of tractive effort by
traction motors that use the provided electricity. These locomotive
controllers also manage fuel use and efficiency, emissions
production, and other aspects of the locomotive operation. MU
controls relay throttle and brake instructions from a first
locomotive (master or "A" units) to one or more second locomotives
(slaves or "B" units), where these instructions are independently
interpreted by the respective locomotive controller and tractive
effort is provided independently by each locomotive of a consist.
MU locomotives operate independently and do not share power or
engine control signals, nor do they permit a first locomotive
controller to make requests of a second locomotive controller.
Similarly, legacy locomotive controllers of locomotives operating
in MU fashion do not share operational data and do not make
operational decisions about the operations of a first locomotive
controller based upon the operational characteristics of the second
locomotive controller.
[0004] Legacy locomotives comprise those locomotives which do not
have a locomotive controller that is able to manage multiple
simultaneous power generation sources. Legacy locomotives which
support multiple simultaneous power generation sources are called
"genset" locomotives, as described above.
[0005] FIG. 1 is a block schematic diagram illustrating a typical
legacy DC locomotive system 10. The DC locomotive system 10
includes two control loops: an engine control loop 12 and an
electrical-power control loop 14. These control loops are
implemented by legacy locomotive controller 16. A legacy locomotive
controller 16 is an analog electro-mechanical assembly, a digital
microcontroller-based control system that implements these control
loops, or a combination of these technologies. A throttle or
"Notch" setting or notch request 18 is set by the operator and is
an input to the legacy locomotive controller 16. In the engine
control loop 12, the Notch setting 18 is an encoded request for a
particular locomotive power setting and is used by the legacy
locomotive controller 16 to calculate a set-point for engine speed.
The engine control loop 12, implemented by the legacy locomotive
controller 16, is responsible for tracking and managing that speed.
The electrical control loop 14 of legacy locomotive controller 16
uses the Notch setting 18 to determine a power set-point. The
legacy locomotive controller 16 then manages the electrical output
power of the engine/generator combination to that power set-point.
Collectively, these systems are called "legacy locomotive control
systems".
[0006] The high-level schematic diagram for a typical AC locomotive
is very similar to that shown in FIG. 1 with the exception that
instead of the DC bus wiring directly to DC motors, the power
source for the AC induction motors is controlled by a separate AC
controller. The AC controller is responsible for distributing power
(and reducing it during knockdowns). In an AC locomotive, the DC
bus voltage is stored on capacitors which ensure stable power while
the AC induction inverters switch the power to the wheels. Thus,
for an AC locomotive, the power control portion is similar to that
of a DC locomotive.
[0007] Legacy locomotive controllers can be generally characterized
as outputting engine control voltages (e.g., RPM and generator
excitement voltages), receiving sensor input of operational
information (e.g., sensor readings indicating actual engine RPM,
some fault information, and, in some cases, power bus sensor
readings), and then acting to adjust the operation of the engine by
varying its control voltages. In locomotives that include multiple
engine-generator sets, the legacy locomotive controller manages the
locomotives engines and provides power blending by controlling the
amount of power and voltage provided by each engine to the common
power bus, which permits the provided power to be combined on the
power bus.
[0008] Legacy locomotive controllers are constructed with a basic
assumption that the power sources that they control are provided in
a fixed arrangement. If a legacy locomotive controller is unaware
of multiple possible power sources, then the use of an external
power tender can only be provided on an "all or nothing" basis,
where the power tender directly substitutes for the
engine-generator on the locomotive chassis. Given the complex
nature of locomotive control and the interrelatedness of locomotive
loads such as traction motors and blowers, a locomotive's
controller, its engine-generator, and an external power tender
cannot "share" the generation requirement, with a portion of the
power coming from the engine-generator, and remainder of the power
coming from the external power tender without the legacy locomotive
controller being aware of the power tender and the amount of power
it produces. As just one example, the heat generated by the
locomotive's electric traction motor must be continuously rejected
from the motor apparatus to prevent motor damage and catastrophic
failure including fires in the worst cases. In order to reject this
heat from the traction motors, locomotives use forced air blower
systems to pass air through the internal structure of each traction
motor. The power to turn the traction motor blowers comes from the
locomotive diesel engine in either mechanical or electrical form.
In both instances, the drive speed of the motor blowers is related
to the operating speed or power output of the locomotive and
adjusting the locomotive diesel engine to compensate for power
provided from external sources will reduce the cooling of the
traction motors without reducing their actual load (and heat
generation).
[0009] If the legacy locomotive controller is not programmed to be
aware of an additional power source programmed to deliver power to
the bus, the legacy locomotive controller will recognize the
additional power available on the locomotives power bus and either
fault, mis-control one or more power sources or loads, or even turn
off the locomotive's engine-generator. In addition, the addition of
unexpected auxiliary power sources may result in improper control
of other locomotive systems tied to the locomotive engine-generator
or to the amount of power being used by locomotives loads (e.g.,
blowers, auxiliary power), thereby resulting in a non-functioning
locomotive.
[0010] While some legacy locomotive controllers have been
configured to control static arrangements of dissimilar power
sources (such as an engine-generator, fuel cell, gas turbine, or
batteries) in an effort to reduce emissions and fuel costs, extend
locomotive limits, and improve the efficiency of locomotive power,
these static arrangements have failed due to the lack of
operational flexibility required for day-to-day operation of
locomotives and/or operational limitations (such as locomotive
range, power production limitations, and requiring support for
multiple fuel sources).
[0011] Further, the legacy locomotive controllers of existing
diesel engines are configured with built-in assumptions regarding
the power curve and engine settings (e.g., RPM, generator
excitement) that are used to produce specific power/voltages. These
operating assumptions are violated by physical limitations induced
by separating the power tender from the locomotive chassis (as
described above), and by logical considerations that power tenders
may have different operating parameters and settings (e.g.,
differing engine type, characteristics, fuels). In current
configurations, power tenders and locomotive controllers must be
operated as a single, non-varying consist because of inherent
limitations in the locomotive control and the lack of locomotive
controller knowledge of differing power tenders and each power
tenders instructions and operational characteristics. The lack of
flexibility of these older control systems prohibits the use of
newer, more desirable, power sources capable of operating with
alternative fuel sources and limits operational flexibility made
available by swapping out of service units (which takes an entire
locomotive/power tender combination out of service).
[0012] Newer locomotive power control systems have evolved from
electro-mechanical to digital controls offering a variety of new
options for power control that perform the same functions as the
older electro-mechanical control systems, as well as add new power
management and train control functions in order to improve
performance and fuel efficiency. However, the cost and technical
integration challenges of retrofitting these digital controllers to
pre-existing (legacy) locomotives is problematic and are often
prohibitive. Generally, this retrofit requires the wholesale
replacement of the locomotive control system and some of the
locomotive control circuits, as well as substantial modifications
to the locomotive engine, generator, and other electrical
components on the locomotive. Furthermore, these types of changes
typically cause a reclassification of the locomotive and require
recertification of the locomotive power plant for safety and
emissions. The recertification process requires that the engine
emissions be updated to current EPA requirements, which adds
additional cost. Combined, these costs are prohibitive.
[0013] In light of the above, it would be advantageous to maintain
the ability to operate an existing locomotive engine using the fuel
for which it was originally designed while adding the ability
provide extra power to that locomotive from an auxiliary power
source.
[0014] It would further be desirable to design an apparatus and
method for providing an auxiliary power source for a locomotive
that can be integrated with existing electro-mechanical locomotive
controls to provide the benefits of being able to incorporate power
from alternative fuel sources without replacing or reprogramming
the pre-existing locomotive controller.
[0015] It would also be desirable to design an apparatus and method
that effects proper control of locomotive systems tied to the
locomotive engine-generator, such as traction motors and traction
blower motors, when an auxiliary power source is used to deliver
power to the locomotive power bus.
BRIEF DESCRIPTION OF THE INVENTION
[0016] Embodiments of the invention overcome the aforementioned
drawbacks by providing a method and apparatus for retrofitting a
legacy locomotive control system with an intercept locomotive
controller to enable the use of situational-appropriate auxiliary
power sources and permit railroad locomotives to make
cost-advantaged use of alternative power sources when it is cost
effective to do so without reprogramming or replacing the existing
legacy locomotive controller.
[0017] Embodiments of the invention relate generally to the
management of locomotives utilizing one or more auxiliary power
units and, more particularly, to a method and apparatus for
equipping an existing locomotive with an intercept locomotive
controller designed to manage auxiliary power sources and interface
with the existing legacy locomotive controller of the
locomotive.
[0018] In accordance with one aspect of the invention, a locomotive
assembly includes a power bus, a locomotive, and an intercept
locomotive controller. The locomotive includes a primary power unit
coupled to the power bus and a legacy locomotive controller
programmed to transmit a control command to the primary power unit.
The intercept locomotive controller is electrically coupled between
the locomotive controller and the primary power unit and is
programmed to intercept an initial locomotive control signal
transmitted from the legacy locomotive controller to the primary
power unit indicating an amount of locomotive power, modify the
initial locomotive control signal, and transmit the modified
control signal to the primary power unit.
[0019] In accordance with another aspect of the invention, a method
of controlling a locomotive includes relaying an initial locomotive
control signal from a legacy locomotive controller designed to
control at least one power source on the locomotive to an intercept
locomotive controller, the initial locomotive control signal
comprising an encoded request for a locomotive power setting. The
method also includes determining a power output corresponding to
the locomotive power setting and allocating the power output
between the at least one power source on the locomotive and an
auxiliary power source. The method further includes transmitting a
modified locomotive control signal to the at least one power source
on the locomotive based on the power output allocation, the
modified locomotive control signal different from the initial
locomotive control signal and transmitting an auxiliary command
signal to the auxiliary power source based on the power output
allocation.
[0020] In accordance with yet another aspect of the invention, a
computer readable storage medium having stored thereon a computer
program comprising instructions which, when executed by at least
one processor, cause the at least one processor to receive an
initial locomotive power setting command from a locomotive
controller, the initial locomotive power setting command indicating
a desired tractive power. The instructions also cause the at least
one processor to modify the initial locomotive power setting
command and transmit the modified locomotive power setting command
to a locomotive power source. The instructions further cause the at
least one processor to receive a sensor signal corresponding to the
modified locomotive power setting command, modify the sensor signal
to match an expected sensor signal for the initial locomotive power
setting command, and transmit the expected sensor signal to the
locomotive controller.
[0021] These and other advantages and features will be more readily
understood from the following detailed description of preferred
embodiments of the invention that is provided in connection with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings illustrate preferred embodiments presently
contemplated for carrying out the invention.
[0023] In the drawings:
[0024] FIG. 1 is a schematic block diagram illustrating a control
system of a prior art diesel genset locomotive.
[0025] FIG. 2 is a schematic diagram of a locomotive assembly
including a legacy locomotive with an intercept locomotive
controller and an auxiliary power unit assembly, in accordance with
an embodiment of the invention.
[0026] FIG. 3 is a schematic diagram of an exemplary intercept
locomotive controller usable with the locomotive assembly
illustrated in FIG. 2.
[0027] FIG. 4 is a schematic block diagram of select components of
the locomotive assembly of FIG. 2, in accordance with an embodiment
of the invention.
[0028] FIG. 5 illustrates an exemplary control process for
controlling a locomotive assembly, such as the locomotive assembly
of FIG. 2, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0029] Embodiments of the invention disclosed herein include an
"intercept" locomotive controller integrated within the existing
control circuitry of the control system of a legacy locomotive,
such as legacy locomotive 10 of FIG. 1. As described in detail
below, the intercept locomotive controller receives control and
sensor inputs from a variety of sources, including one or more
pre-existing locomotive controller outputs, such as, for example
Notch settings, and provides sensor or other outputs to
pre-existing locomotive controller inputs and locomotive power or
other locomotive equipment. Using the output signals received from
the legacy controller, the intercept locomotive controller
recalculates the power allocation between the legacy locomotive
engines and to one or more auxiliary power units and transmits
differing signals to the legacy locomotive engines and to one or
more auxiliary power units. The intercept locomotive controller
also receives signals from sensors on the locomotive and sensors
located on one or more auxiliary power unit (APU) assemblies
coupled to the locomotive and synthesizes those signals into
signals expected by the legacy locomotive controller.
[0030] Because the intercept locomotive controller is configured to
intercept both signals output from the legacy locomotive controller
and signals input to the legacy locomotive controller, such as
sensor inputs for example, the intercept locomotive controller can
interoperate with the existing legacy locomotive controller without
making modifications to the existing legacy locomotive controller
or replacing the legacy locomotive controller with a "genset" style
locomotive controller that has been modified to interoperate with
one or more removable auxiliary power units. Therefore, this
"intercept" controller architecture has the advantage of enabling
legacy locomotives to interface with auxiliary power units and
operate with lower costs and with reduced emissions, and without
incurring large retrofit expenses or recertification costs. Also,
when auxiliary power is not available, the intercept locomotive
controller can pass the signals through directly without
modification to their legacy destination and the legacy locomotive
will work in its original factory mode.
[0031] Referring now to FIG. 2, a locomotive consist or locomotive
assembly 110 that includes an intercept locomotive controller 162
is illustrated according to one embodiment of the invention. As
shown, locomotive assembly 110 includes a locomotive 112 that is
coupled to auxiliary power unit assembly 48 via power and control
cables 100, 142. A locomotive consist is defined for purposes
herein as an arrangement of locomotives and auxiliary power units,
coupled together, which share control and power connections between
at least one locomotive and at least one auxiliary power unit. For
purposes of illustration, several exemplary configurations of
consists may be defined as follows:
[0032] A-B Consist: One locomotive coupled to one auxiliary power
unit. The auxiliary power unit provides at least some, but not all,
of the electrical power required by the locomotive.
[0033] A-B-A Consist: Multiple locomotives are coupled to one
auxiliary power unit. The auxiliary power unit provides a least
some, but not all, of the electrical power required by each of the
locomotives.
[0034] A-B-B Consist: One locomotive is coupled to multiple
auxiliary power units. The auxiliary power units together provide
at least some of the electrical power required by the
locomotive.
[0035] Referring first to the locomotive portion of the locomotive
assembly 110 of FIG. 2, locomotive 112 includes a locomotive
control system 113 having a legacy locomotive controller 114 and an
intercept locomotive controller 162. Similar to legacy locomotive
controller 16 (FIG. 1), legacy locomotive controller 114 is
configured to manage a pre-defined arrangement of one or more fixed
locomotive engine-generator sets 116 designed to operate in
response to received control signals from legacy locomotive
controller 114. Such predefined and static operating arrangements
may be stored within legacy locomotive memory 115. The number of
engines/generator sets 116 included within locomotive 112 and the
associated control inputs and outputs are simplified for clarity in
this illustration. As such, while locomotive 112 is illustrated as
including a single locomotive engine-generator set 116, locomotive
112 may include additional fixed power sources according to various
embodiments. The legacy locomotive controller 114 provides a
plurality of control inputs and outputs between the legacy
locomotive controller 114, the engine/generator set 116, and
various sensors 122, 140 that monitor the operation of the
engine/generator set 116, the traction bus 124, and fraction motors
128, as described in additional detail below.
[0036] Locomotive engine-generator set 116 includes a respective
diesel engine 118, generator 120, and sensor system 122. While
element 120 is described as a generator herein, alternators may be
substituted for generators in the power generation system as
understood by those skilled in the art. Generator 120 produces
electricity for delivery to a DC locomotive fraction bus 124 and an
auxiliary power bus 126. According to one embodiment, generator 120
is excited through a silicon controlled rectifier (SCR) 121 (shown
in phantom). In an alternative embodiment, generator 120 is excited
using a pulse-width-modulated (PWM) signal. Generator 120 is
configured to convert the mechanical energy provided by engines 118
into a form acceptable to one or more traction motors 128 (DC or AC
type) configured to drive the plurality of axles coupled to the
driving wheels 130 of locomotive 112, and to provide DC or AC power
to the respective auxiliary power bus 126. According to one
embodiment, traction motors 128 are cooled via a traction motor
blower 204 (FIG. 4), which may be coupled to a power take off of
diesel engine 118 or powered by electrical power derived from
diesel engine 118, according to various embodiments.
[0037] In traditional legacy locomotive engine configurations,
locomotive engine-generator set 116 is operated in response to a
throttle position input sensor 134 which indicates the position of
the throttle as controlled by the operator on an operator interface
136. Operator interface 136 may also include an optional operator
engine start input 138 (shown in phantom) where the operator can
directly or indirectly instruct legacy locomotive controller 114
(e.g., via a keypad (not shown)) with regard to operation of
engines 118 or termination of operation of the engines 118.
[0038] The intercept locomotive controller 162 is positioned
between the equipment control inputs of legacy locomotive
controller 114 and its locomotive subsystems (e.g., engines,
generators, sensors, traction motor controllers, collectively
referred to herein as "locomotive equipment") through one or more
interfaces. The intercept locomotive controller 162 receives
equipment control inputs originally directed to the legacy
locomotive controller 114 or other locomotive equipment and outputs
synthesized values to the respective legacy locomotive controller
114 and locomotive equipment to effect the control of integrated
locomotive equipment and APUs 50. These control inputs include
information transmitted from user interface 136 to legacy
locomotive controller 114 and information transmitted to legacy
locomotive controller 114 from power sensors 140 and locomotive
engine/generator sensors 122 that provide information in the form
of analog electromagnetic signals and/or digital signals, which are
read by (and converted to appropriate form by) the intercept
locomotive controller 162. According to various embodiments,
intercept locomotive controller 162 includes circuitry to convert
the digital and analog signals to/from a form usable by the
intercept locomotive controller 162. As one skilled in the art will
recognize, this "intercept" paradigm may be extended to the control
of any locomotive equipment as well as to the control of external
locomotives (using an MU interface). The various input and output
interfaces of intercept locomotive controller 162 are illustrated
and described in more detail with respect to FIGS. 3 and 4.
[0039] Power sensors 140 on the locomotive traction bus 124 and
auxiliary power bus 126 coupled to intercept locomotive controller
162 through control and sensor circuits provide information on the
amount of power actually being provided on the busses 124, 126
and/or to traction motors 128. These sensors are well known by
those skilled in the art and may provide digital, analog, or a
combination of digital and analog outputs to intercept locomotive
controller 162.
[0040] Locomotive 112 also includes an engine start and stop
control 132 which interfaces with legacy locomotive controller 114.
In some embodiments, the engine start and stop control 132 is also
connected to the intercept locomotive controller 162 and the
intercept locomotive controller 162 provides a synthesized engine
start and stop control input to the legacy locomotive controller
114, as described in more detail below with respect to FIG. 4.
[0041] As shown in FIG. 2, locomotive 112 is connected to an
auxiliary power unit assembly 48, which includes an auxiliary power
unit (APU) 50 that is designed to interface with one or more
locomotives, such as a diesel locomotive and one or more
interchangeable gaseous fuel assemblies 52. As used herein,
"gaseous fuel" means fuels in liquid or gaseous state (depending
upon current temperature and pressure), where the fuel is normally
in a gaseous state at standard temperature and pressure. In many
cases, these fuels are hydrocarbons such as natural gas, propane,
or syngas. Gaseous fuel may also be, for example, compressed or
liquefied hydrogen, producer gas, methane, butane, and the like. In
the embodiment shown, auxiliary power unit assembly 48 includes one
or more fuel assemblies 52 stacked atop the container 54 housing
APU 50, which is secured to a rail car 56. However, one skilled in
the art will recognize that fuel assemblies 52 and APU 50 may be
arranged in other configurations in alternative embodiments. As
described in detail below, APU 50 provides additional power to the
connected locomotive(s) 112 in the locomotive consist 110 under
direction of at least one intercept locomotive controller 162. As
used herein, the term "auxiliary power unit" or "APU" is used to
refer to an autonomously controlled device capable of generating
and supplying tractive power to a locomotive. The term
"autonomous," as used herein, refers to an APU that able to act
independently and control the internal operations of the APU
independently in response to external requests, and wherein the
internal workings of the APU are opaque or unknown to external
control systems. Autonomous APUs and associated fuel assemblies are
described in additional detail in U.S. Non-Provisional patent
application Ser. No. 13/838,787, which is incorporated by reference
herein.
[0042] APU 50 includes an auxiliary engine-generator set 82 having
an engine 78 and an auxiliary alternator or generator 84 that is
electrically connected to an electrical manager 86, which manages
the electricity generated by APU 50 and provides that electricity
to a specific locomotive 112 via a power cables 142. When APU 50 is
connected to more than one locomotive at a time, multiple
electrical managers (one per connected locomotive) may be used in
order to electrically isolate each locomotive. In operation, APU
controller 70 receives and responds to requests from locomotive
control system 113 and may also provide periodic or asynchronous
notifications to locomotive control system 113. For example, APU
controller 70 may report the presence or status of APU 50 to
locomotive control system 113, provide identifying information
about one or more aspects of APU 50 (e.g., its identification type,
a serial number), its engines 78 (e.g., engine type, rated
horsepower, serial number), and the attached fuel assemblies 52
(e.g., fuel assembly ID, date of last pressure test). The APU
controller 70 may further report the amount of power the APU 50 is
able to generate in response to a power request. APU controller 70
also receives signals from sensors 71 located within APU 50 and may
also receive instructions, such as a start request, an emergency
stop request, and a power request from locomotive control system
113, as described in additional below.
[0043] Optionally, APU 50 may be configured to provide identifying
information to intercept locomotive controller 162 via an optional
control interface 72 (shown in phantom in FIG. 4). This identifying
information includes identifying information from APU 50 as well as
identifying information from fuel assemblies 52 coupled to APU 50.
Identifying information may include an equipment configuration of
APU 50, the amount and/or cost of power that is currently being
generator and/or can be generated by the APU 50, and a cost of fuel
within the pressure tanks 60 of fuel assembly 52 as examples. Based
on the identifying information received from APU 50 and a current
total power demand of locomotive 112, intercept locomotive
controller 162 makes a determination as to how to allocate power
generation between locomotive engine-generator sets 116 and
auxiliary power unit 50. According to one embodiment, APU 50 is
programmed to periodically transmit identifying information to
intercept locomotive controller 162, such as, for example, (as a
notification) at predefined time intervals. Intercept locomotive
controller 162 may also communicate with one or more fuel
assemblies 52 (as optional locomotive equipment or via an APU 50
interface), which provide gaseous fuel to one or more of the
locomotive engines 118 and/or APU 50. Fuel assemblies 52 also
provide sensor information regarding fuel state, fuel type, and
fuel costs to intercept locomotive controller 162.
[0044] Output power generated by auxiliary generator 84 is
delivered to DC bus 124 of locomotive 112 via power cables 100 and
control cables 142, which are coupled between APU assembly 48 and
locomotive 112 via respective contactor boxes 206, 208. The number
of control cables 100 is determined based on design specifications
for the amperage and interconnection between locomotive 112, APU
50, and fuel assemblies 52. As shown in FIG. 2, a disconnect sensor
144 is coupled to power cables 142, which electrically connect
locomotive 112 and APU 50. Disconnect sensor 144 is configured to
sense a connection status of APU 50 with locomotive traction bus
124. Should a decoupling occur between locomotive 112 and rail car
56 and/or a disconnection occur between power cables 142 and
locomotive traction bus 124, disconnect sensor 144 will transmit an
alert signal to at least one of APU controller 70, legacy
locomotive controller 114, and intercept locomotive controller 162
indicating the disconnection.
[0045] In some embodiments, intercept locomotive controller 162
provides APU control instructions on an optional dedicated APU
control interface 72 (shown in phantom in FIG. 4). In a preferred
embodiment, this control interface 72 provides signaling that is
electromagnetic interference (EMI) resistant (e.g., CANbus). In
other embodiments, control cables 100 may include converters
(described above) that convert locomotive controller engine control
voltages (e.g., RPM, generator excitement) to/from EMI resistant
signaling means. In other embodiments, control cables 100 may
include converters (not shown) to convert locomotive controller
engine control voltages (e.g., RPM, generator excitement) to APU
controller instructions. These converters may be implemented
individually or in series as desired to provide a signaling path
between the intercept locomotive controller 162 and APU control
interface 72.
[0046] The intercept locomotive controller 162 is optionally
connected to one or more fraction bus sensors 140 and meters via
control and sensor circuits. These sensors and meters monitor the
amount of power placed on the traction bus 124 by an APU 50.
Similarly, an intercept locomotive controller 162 may provide a
control circuit effective to control the operation of an APU 50.
When connected in this way, the controller 70 of APU 50 may receive
instructions from the intercept locomotive controller 162 to
provide a specific amount power to the locomotive traction bus 124
and/or the auxiliary power bus 126. For clarity of illustration,
the connections are shown for a single external power unit or APU
50. Sensors, meters, and control circuits may be replicated for
each APU 50 if a plurality of APUs 50 are utilized. Any control
and/or sensor circuit may optionally be electrically connected to a
common control and sensor interface (not shown), which is
electrically connected to intercept locomotive controller 162 in
order to minimize the number of discrete control and sensor
circuits.
[0047] Referring now to FIGS. 3 and 4, the control system
configuration and operation of intercept locomotive controller 162
are described according to various embodiments of the invention. As
referenced above and described in detail below, the intercept
locomotive controller 162 is positioned between a legacy locomotive
controller 114 and its locomotive equipment, and receives and
processes legacy locomotive controller instructions to the engines,
alternator/generators, traction motor controllers, and other
locomotive equipment, and transmits the same or altered
instructions to the locomotive equipment and one or more APUs 50.
The intercept locomotive controller 162 also receives responses and
sensor inputs from one or more APUs and locomotive equipment,
integrates these responses, synthesizes any necessary information
within processor 166, and presents the integrated and/or
synthesized information to the legacy locomotive controller 114.
According to various embodiments, intercept locomotive controller
162 is operable with digital, analog, or a combination of both
digital and analog control and sensor inputs and outputs.
[0048] Intercept locomotive controller 162 includes various
interfaces that permit the intercept locomotive controller 162 to
perform electronic monitoring, control, and reporting of locomotive
and APU operation. For example, intercept locomotive controller 162
includes one or more receive engine interfaces 168, which are
connected to the legacy locomotive controller 114 and receive
engine and/or alternator/generator settings from the legacy
locomotive controller 114. Collectively, these signals encode an
amount of power requested by the legacy locomotive controller 114
of a power source, such as, for example, a specific engine and
alternator/generator pair. According to various embodiments,
intercept locomotive controller 162 may include one or more receive
engine interfaces 168 depending upon the number of power sources
the legacy locomotive controller 114 is controlling. Intercept
locomotive controller 162 further includes one or more send sensor
interfaces 170, which are connected to sensor inputs of the legacy
locomotive controller 114. The intercept locomotive controller 162
sends synthesized sensor values to the legacy locomotive controller
114 using this interface 170.
[0049] Intercept locomotive controller 162 also includes one or
more send engine/generator interfaces 172, which are connected to
the control inputs of the locomotive engine(s) 118 and generator(s)
120. It is over these interfaces 172 that the intercept locomotive
controller 162 configures the engine and generator settings of the
locomotive engines 118. Intercept locomotive controller 162 further
includes at least one APU command interface 174, which is operably
connected to an APU 50 as described herein. The intercept
locomotive controller 162 communicates with one or more APUs 50
over this interface 174.
[0050] Interfaces 172 and 174 connect interface locomotive
controller 162 to engine/generator sets 116 and APUs 50 using
control and sensor circuits constructed to convert the digital
and/or analog singles from the respective power sources to/from a
form usable by the intercept locomotive controller 162. In some
implementations, interface 172 leverages control and sensor
circuitry that is a portion of pre-existing wiring already present
in the locomotive 112. In some implementations, the engine control
circuitry includes engine RPM control circuits, the generator
control circuitry comprises generator excitation control circuitry,
and sensor inputs include engine RPM and generator output readings.
Note that although the sensor inputs are illustrated as a single
circuit, alternative embodiments may include a plurality of
circuits.
[0051] Intercept locomotive controller 162 additionally includes
one or more receive locomotive sensor input interfaces 176, which
are operably connected to DC traction bus sensors 140 as well as
one or more additional sensors 200 on the locomotive 112. According
to various embodiments, the number of locomotive sensor input
interfaces 176 may vary based on the number of sensors the legacy
locomotive controller 114 is provided with. Additional locomotive
sensors 200 may include, as non-limiting examples, such sensors as
overheat, engine RPM, fraction motor temperature sensors, traction
motor power usage sensors, auxiliary bus power sensors, and the
like. Optionally, the sensor inputs may include an interconnection
to the interface and/or user interface of the MU, which permits the
intercept locomotive controller 162 to receive control inputs from
sources using the MU and/or user interface components (e.g., a
throttle, brake level, or user interface panel)
[0052] The intercept locomotive controller 162 further optionally
includes one or more send locomotive equipment interfaces 178
connected to locomotive equipment such as traction motors, traction
motor controllers, or other locomotive equipment interfaces that
are operably connected to the locomotive equipment in order to
permit the intercept locomotive controller 162 to control one or
more locomotive equipment components. Optionally, the send
locomotive equipment interfaces 178 may include an interconnection
to the MU interface and/or user interface 136 of the locomotive
112, which permits the intercept locomotive controller 162 to send
control information to other locomotives using the MU and/or user
interface components (e.g., a user interface panel). While
intercept locomotive controller 162 is illustrated in FIG. 3 as
including five interfaces, one skilled in the art will recognize
that the number of interfaces may be varied based on design
specifications and system configuration.
[0053] Intercept locomotive controller 162 also includes one or
more memories 164 within which intercept locomotive controller 162
may store identifying information used to uniquely identify legacy
locomotive controllers 114 to which it is connected. This
information may be used for the intercept locomotive controller 162
to configure its inputs and outputs, and to configure power
allocation and similar algorithms. Intercept locomotive controller
162 also may store information regard standardized and specific
locomotive equipment characteristics. For example, standardized
information about locomotive equipment characteristics may include
a power curve specific to one or more classes of engines,
information describing generating and/or power capacity of one or
more classes of auxiliary power unit assemblies, acceptable fuel
types for use with a particular auxiliary power unit, shutdown
delay interval, sensor types and value ranges/meaning, and the
like. Similarly, intercept locomotive controller 162 may store
specific information about the locomotive within which it is
installed, such as connected locomotive equipment as well as
operating requirements, parameters, control instructions, etc.
associated with the respective locomotive equipment. For example,
the information may include a list of attached locomotive
engines/generators, their capabilities and power curves, fuel
efficiency metrics for each of the specific engines, sensors
connected and their expected values and ranges (and meanings of
these values), and the like.
[0054] Intercept locomotive controller 162 may also store
information about one or more classes of auxiliary power units
and/or a specific auxiliary power units, including the capabilities
of classes of auxiliary power units (e.g., capability, interconnect
requirements, cost of power, fuel types) and specific instances of
auxiliary power units. Specific information stored may include
information about one or more aspects of a particular auxiliary
power unit assembly (e.g., its identification type, a serial
number), its engines (e.g., engine type, rated horsepower, serial
number), and the attached fuel assemblies (e.g., fuel assembly ID,
date of last pressure test), the cost of power provided by the
auxiliary power unit assembly, any limits on the use of power from
auxiliary power unit assembly, and information related to the
operation of auxiliary power unit assembly, including historical
sensor readings, power produced and delivered, and operation,
inspection, and use history.
[0055] Within memory 164 of intercept locomotive controller 162,
one or more configuration tables are stored. These configuration
tables include instructions for communicating with specific types
and models of engine/generators, external power units, sensors, and
locomotive control units, including control parameters, input and
output value ranges, and other related information. The memory 164
of intercept locomotive controller 162 may also include
input/output interface parameters that are used to associate
specific interfaces with the intercept locomotive controller
control logic, any adjustments in value used to interface to those
interfaces, and similar information. In some implementations, the
memory 164 of intercept locomotive controller 162 may further
include control strategy information which is used by the intercept
locomotive controller 162 to allocate power requirements across
multiple power sources. For example, a simple control strategy
might be to run the legacy locomotive engine/generator set 116 at
idle in order to produce power for the auxiliary bus 126, and
supply all other power requirements from the APU 50.
[0056] Memory 164 of intercept locomotive controller 162 may
include an internal database of legacy locomotive control systems
and equipment, including engine/generator classifications and
settings, legacy locomotive controller information, sensor types,
etc. This information is used by the intercept locomotive
controller 162 to configure its responses to inputs and to properly
configure its outputs. For example, the intercept locomotive
controller database may include information on one or more legacy
locomotive controller types, which may provide information as to
its control outputs (which are connected to the intercept
locomotive controller inputs), their expected values, and any
expected responses and/or sensor values. The database may also
associate a specific control regime or control plan for use with a
specific legacy locomotive controller. Similarly, the intercept
locomotive controller database may include information about:
a) engine/generator combinations, including control specifications
for engine/generator settings required to produce specific power
levels, expected sensors and sensor values associated with specific
engine/generator performance, etc., b) APU settings/command
interface specifications, including APU identification databases,
APU class performance characteristics, APU command interface and
response settings, including APU interface and protocol
specifications for communicating (e.g., sending commands, receiving
responses) with one or more APUs, c) traction motor controller
settings and related sensor values, including communication
protocols used, control formats and settings to instruct a fraction
motor controller, and expected sensor values and their control
interpretations for traction motors (temperature, power used,
etc.), d) fuel types and energy contents, for use with managing
removable fuel assemblies, e) fuel assembly communications
parameters, including communication protocols used, control formats
and settings to instruct a fuel assembly controllers, and expected
sensor values and their control interpretations, f) operating plan,
including power allocation plans as described below, and g)
locomotive equipment configurations, including type of equipment,
corresponding inputs and output interfaces of the intercept
locomotive controller 162, and conversion information.
[0057] In one embodiment, intercept locomotive controller 162 is a
PLC or micro-controller, along with associated memories and
volitile registers and as well as the associated digital and analog
interfaces in order provide control electronics for the electronic
monitoring, control and reporting of locomotive engine/generators
and sensors.
[0058] Referring now to FIG. 4 and with continued reference to FIG.
2 and FIG. 3, the operation of intercept locomotive controller 162
within the context of the locomotive consist 110 is set forth. The
legacy correlation between primary engine RPM (or throttle setting)
and the amount of electricity generated is stored within legacy
locomotive controller 114. Legacy locomotive controller 114 manages
the amount of apparent power present on the busses 124, 126 by
requesting changes in engine RPM and generator excitement (e.g., by
changing the control signals) and by measuring the amount of power
reported by the intercept locomotive controller 162 as being
present on the various busses 124, 126. Legacy locomotive
controller 114 also calculates and manages locomotive location and
anticipated power needs and issues adjusted power configurations to
the locomotive equipment. These adjusted power configurations are
intercepted by the intercept locomotive controller 162 and further
adjusted to integrate the use of one or more APUs 50.
[0059] In operation, intercept locomotive controller 162
periodically receives engine/generator control signals indicating
requested engine RPM and generator excitement from legacy
locomotive controller 114 through engine control interface 168.
Whether the engine control signal received is continuous or
episodic depends upon the engine/generator(s) 118, 120 and legacy
locomotive controller 114 installed in the locomotive. Upon receipt
of an engine/generator control signal, intercept locomotive
controller 162 compares the current state and value(s) of the
engine/generator control signal(s) against a previous state of the
engine/generator control signal(s) to determine if one or more of
the values have changed from previous settings. If there are no
differences from the previous engine/generator control signal(s),
then the intercept locomotive controller 162 does not initiate any
changes in its settings. If, on the other hand, there are changes
in the engine/generator control signal(s) received, the intercept
locomotive controller 162 may take one or more of the following
actions:
A) look up the engine control interface type in an intercept
locomotive controller 162 memory to determine the meaning of the
control signal(s) received. This permits the intercept locomotive
controller 162 to calculate the amount of power the legacy
controller 114 is requesting from the respective engine/generator
set 116; B) calculate the change in power requested, and perform a
power allocation (or other) operation between two or more power
sources, such as, for example, engine/generator set 116 and APU 50
as described herein; C) store the results of the power allocation
(or other) operation for subsequent use in processing sensors; and
D) output engine/generator control signals and APU control signals
to the send engine/generator interface 172 and to the APU control
interface 72 via interface 174 in accordance with the results of
the power allocation operation in order to cause the power sources
to provide the allocated amount of power or perform other
operations.
[0060] Similarly, the intercept locomotive controller 162
intercepts signals from power sensors 140, and locomotive
engine/generator sensors 122 that indicate operational information
for the locomotive control system 113, such as, for example, on the
amount of power actually provided by APUs 50, and the settings
and/or operational conditions of other locomotive equipment, and
the status and/or operation of locomotive engine-generator set 116
(e.g., various parameters of engine 118 such as
revolutions-per-minute (RPMs), operating power output, temperature
and other engine operating parameters). The intercept locomotive
controller 162 receives this information through sensor interface
176, integrates the information to an integrated set of sensor
values (possibly changing their values or providing synthesized
values), and forwards the integrated and synthesized sensor
reading(s) to the legacy locomotive controller 114 and locomotive
equipment through sensor interface 170. The intercept locomotive
controller 162 permits the legacy locomotive controller 114 and
existing locomotive equipment (e.g., locomotive engine generator
set 116) to operate as "normal", while providing additional
features such as the integration of one or more APUs 50 to the
locomotive consist 110.
[0061] Whether the sensor signal received by intercept locomotive
controller 162 through sensor interface 176 is continuous or
episodic, or in analog or digital form, may vary depending upon the
sensor being monitored. Upon receipt of an engine/generator control
signal, the intercept locomotive controller 162 compares the
current state and value(s) of the sensor signal(s) against a
previous state of the sensor signal. If there are no differences
from the previous sensor signal(s), then the intercept locomotive
controller 162 does not initiate any changes in its settings. If
there are changes in the sensor signal received, the intercept
locomotive controller 162 takes the following steps:
A) look up the sensor information describing the sensor values and
meanings; B) determine other sensor input values expected, and
obtain sensors values for those sensors as well; C) create a
synthesized sensor value from the input values consistent with the
expected sensor output to the legacy locomotive controller 114; D)
output the synthesized sensor value to the appropriate send sensor
interface 170 (as determined by the locomotive equipment (sensor)
configuration information stored in the intercept locomotive
controller 162); and E) execute power allocation or other
controller functions to manage the locomotive equipment in
conjunction with one or more APUs 50.
[0062] As one example, intercept locomotive controller 162 receives
signals from DC bus sensors 140, engine-generator sensors 122 and,
optionally, other locomotive sensors 200. The sensor values from
the DC bus sensors 140, engine-generator sensors 122, and other
locomotive sensors 200 are compared against the operating plan of
the intercept locomotive controller 162 (and adjustments are made
to settings if necessary), and the sensor values are combined to
produce synthetic sensor values for transmission to the legacy
locomotive controller 114 indicating that the locomotive
engine/generators 118, 120 are producing the requested or desired
amounts of tractive power.
[0063] Intercept locomotive controller 162 includes an Excitation
Split module and a Feedback Join module as part of its control
logic. The Excitation Split module of intercept locomotive
controller 162 takes the excitation requests from the legacy
locomotive controller 114 received via engine interface 168,
determines the power equivalents of the excitation requests from a
configuration table, performs a power allocation process, and
distributes the power allocation instructions between one or more
APUs 50 and one or more diesel generator/alternator sets 116 of the
locomotive 112. The Excitation Split module also uses as an input
values from the APU 50 that indicate the available power from the
APU 50 and from the configuration information of the intercept
locomotive controller 162, which identifies the
excitation/RPM/power produced information for each engine/generator
set 116.
[0064] The Excitation Split module uses the available power from
the APU 50 to determine how much of the excitation request to
distribute to each of the engine/generator set 116. The nominal
case is to distribute as much power as possible to the APU 50. Some
embodiments may make alternate determinations based upon emissions
requirement, fuel costs, etc. If the APU 50 is not present, the
available power from the APU is zero and the Excitation Split
module distributes all excitation requests to the available diesel
engine/generator sets 116. In this instance, the intercept
locomotive controller 162 is fully backwards compatible with the
legacy diesel-only system.
[0065] The Feedback Join module of intercept locomotive controller
162 sums the currents from the alternator 120 and other power
sensors connected to the intercept locomotive controller 162 and
provides an integrated (synthesized) signal to legacy locomotive
controller 114. The legacy locomotive controller 114 thus functions
identically to how it did before. The function of the legacy
locomotive controller 114, which is to compare the system power
against the power set-point, remains unchanged with the addition of
intercept locomotive controller 162.
[0066] According to various embodiments, the multiple power sources
included within locomotive consist 110, including locomotive
engine-generator set(s) 116 and APUs 50, may be configured to add
energy to the DC bus 124 via passive rectification, active
rectification, and/or DC Bus Pulse Width Modulation, as described
below. Each of these methods assume a parallel bus architecture.
Alternative embodiments using a series circuit involve wiring the
alternators in series would require that every alternator we add be
capable of passing the entire system current, which may make the
alternator prohibitively expensive and large. When using a series
circuit, there are no rectifiers to contend with, the final power
given to the system is simply the current multiplied by the sum of
voltages of each generator 120.
[0067] In one embodiment, power from locomotive engine-generator
set(s) 116 and APUs 50 are shared on the DC bus 124 using passive
rectification. In this implementation, the electrical systems of
the APU 50 is configured similarly to the electrical system of the
locomotive 112, such as, for example, a rectified fraction
alternator feeding DC bus 124. The field coil to the APU 50 is
driving by a pulse-width-modulated chopper circuit that can excite
the APU 50 and that is not subject to the waveform phase delays
that a silicon controlled rectifier (SCR) system is. In this
embodiment, whichever generator has the highest voltage at any
particular time is the one driving the DC bus 124. Since there is
ripple of about 15% in the rectified voltage of the DC output,
multiple power sources will drive some power if their voltage is
within 15% of the highest voltage source.
[0068] In another embodiment, power sharing between locomotive
engine-generator set(s) 116 and APUs 50 is effected through active
rectification. In this embodiment, an AC-DC converter having a
voltage rating on the kilovolt scale and a power rating on the
megawatt scale is included within locomotive assembly 110. The
voltage of each APU 50 is controlled through active rectification
with the target voltage being enough to drive the desired
proportional power of the system. Excitation requests from the
Feedback Split module of intercept locomotive controller 162 step
up the voltage of the APU 50 while lack of excitation requests
slowly lowers the voltage.
[0069] Power sharing may also be implemented between locomotive
engine-generator set(s) 116 and APUs 50 through a high-voltage,
high-power switch provided on each APU 50. The APUs 50 are then
operated at a voltage that is higher than the voltage of the DC bus
124. Excitation requests from the Feedback Split module of
intercept locomotive controller 162 close the switch momentarily
and DC power flows from the higher-voltage APU 50 onto the DC bus
124. Modulating the system determines how much energy is added to
the DC bus 124.
[0070] One important aspect of handing the APU controller 70 is
response time to requests from the intercept locomotive controller
162. Locomotive controllers operate in very short duration control
loops, and response time of APUs to locomotive controller requests
is important to the successful operation of a locomotive control
with an autonomous APU 50. Accordingly, in one embodiment the APU
controller 70 provides response times to requests received from the
intercept locomotive controller 162 within a configuration defined
amount of time or be considered non-responsive. A non-responsive
APU controller would be considered a fault condition by the
intercept locomotive controller 162 and be handled accordingly.
Some locomotive controller requests may contain an indication that
the request should be handled quickly (e.g., within 10 msec, 100
msec, 1 sec, or 10 sec, depending upon the type of change), such as
power removal requests being generated in conjunction with wheel
slip or fault events. Other operational issues, such as fuel
amounts crossing a lower threshold, chassis temperature or alarms,
for example, can be handled more slowly. Still other operations,
particularly those that include communications interactions with
fuel assemblies or lengthy calculations, may complete in 10 or more
seconds.
[0071] In one embodiment, the locomotive consist 110 may be
operated to blend power generated from the APU 50 and
engine/generator sets 116. Blending power is advantageous when the
transition of power must be seamless, when the locomotive control
system 113 operates with a limited rate of control changes, or when
one power source has operational characteristics (e.g., response
time) where changes in power provided cannot be reflected within
operationally acceptable response times.
[0072] In such an embodiment, a second power source can be
configured to "follow" a first power source in accordance with a
power allocation plan. For example, if a first power source has a
high electrical inertia compared to a second power source, changes
in electric power demands that require quick responses (such as
wheel slip responses) may be preferentially allocated to the power
source that is able to more quickly respond, followed by an
optional follow-up set of power reallocation to balance loads
between the power sources to more fuel efficient and/or cost
effective power allocations.
[0073] For example, if the APU 50 responds more slowly to a change
in power than locomotive engine/generator, changes in power demand
will be handled by the locomotive control system 113, with power
allocation and subsequent commands to the APU 50 and request to the
locomotive's engine/generator occurring at different times. The
locomotive control system 113 may first configure the
engine/generator set 116 of the locomotive 112 to quickly produce a
differing amount power in response to a changed power request
(either up or down) in order to meet the received power request,
followed by a subsequent APU controller 70 commands to change the
amount of power generated by the APU 50, followed by an (optional)
third change in the locomotive engine/generator settings to "trim"
the amount of power provided to the locomotive consist 110 to again
match the original power request (in light of the changed APU power
generation in response to the APU commands). If the response
times/inertial response of the power units differ, the order and
timing of requests and commands may vary.
[0074] In some embodiments, the intercept locomotive controller 162
is programmed to operate in accordance with one or more defined
operating plans, which instruct the intercept locomotive controller
162 on how to perform power allocations. The operating plan(s) may
be implemented in the control logic of the intercept locomotive
controller 162, as a program element implemented by the processor
166 of the intercept locomotive controller 162, implemented as a
control plan executed by the logic of intercept locomotive
controller 162 and stored in a memory 164 or as part of the
operating plans of the internal database of memory 164.
[0075] According to one embodiment, the operating plan of intercept
locomotive controller 162 is defined as a look-up table that
allocates power between the legacy engine 118 and APU 50 based upon
an input of requested engine RPM. As one example, illustrated in
TABLE 1 below, the intercept locomotive controller 162 outputs two
values based on the received engine RPM input: an RPM for the
legacy engine 118 and a power setting for the APU 50.
TABLE-US-00001 TABLE 1 Input Output Engine RPM Legacy engine RPM
APU setting 164 164 0 kW 400 164 152 kW 500 350 400 kW 600 400 600
kW 700 450 800 kW 800 500 1000 kW
[0076] According to another embodiment, the operating plan of
intercept locomotive controller 162 is defined as a look-up table,
such as, for example, TABLE 2 below, that changes the excitation
voltage of legacy locomotive engine 118 to reduce load (and power
output) while keeping RPMs raised in order to support direct drive
operation.
TABLE-US-00002 TABLE 2 Input Output Engine Legacy engine Excitation
APU RPM RPM Voltage setting 164 164 5.0 V 0 kW 400 350 4.0 V 152 kW
500 400 3.0 V 400 kW 600 450 2.0 V 600 kW 700 500 1.0 V 800 kW 800
600 0.5 V 1000 kW
[0077] An exemplary interface definition table that describes the
actions of the intercept locomotive controller 162 with respect to
intercept and forwarding of sensor values is provided in TABLE 3
below, in accordance with one embodiment of the invention. As
described in additional detail below, TABLE 3 defines the sensors
connected to various receive sensor interfaces of the intercept
locomotive controller 162, and the actions to be taken by the
intercept locomotive controller 162 under various operating
conditions. It is contemplated that the intercept locomotive
controller 162 additionally may take other actions to manage the
locomotive 112 and/or APU 50 as described herein.
[0078] Initially, it is contemplated that the multiple receive
engine interfaces and receive locomotive equipment interfaces
listed TABLE 3 below may be incorporated within respective
multi-input interfaces provided on intercept locomotive controller
162 or individual input interfaces, such as, for example, control
interface 168 (FIG. 3) and sensor interface 176, according to
alternative embodiments. Further, according to various embodiments
the sensor signals listed in the Disposition column of TABLE 3 may
be forwarded from a common send sensor interface, such as send
sensor interface 170 (FIG. 3), or from a number of individual send
sensor interfaces provided on intercept locomotive controller
162.
TABLE-US-00003 TABLE 3 Line Sensor ID Control-Report Model
Interface Disposition 1 Engine RPM Cummins Receive Engine On
change, calculate instructions Interface 1 power requested,
allocate power to consist 2 Generator Cummins Receive Engine On
change, calculate excitement Interface 2 power requested, allocate
instruction power to consist 3 Fault MU Receive Poll 1 s, on
change, process Locomotive fault Equipment 0 4 Traction TempSensor
Receive Poll 1 s, on change, send to Motor Locomotive send sensor
interface Temperature Equipment 1 5 Traction PowerSensor Receive On
change, calculate Motor Draw Locomotive reported power, set value
Equipment 2 to calculated power and send to send sensor interface 6
DC bus power PowerSensor Receive On change, recalculate Locomotive
power provided, send Equipment 3 calculated power to send sensor
interface 7 Engine 1 RPM Cummins Receive On change, recalculate
Locomotive power, send calculated Equipment 4 RPM to send sensor
interface, process power change 8 Generator 1 Cummins Receive On
change, set to voltage Locomotive requested power for engine/
Equipment 5 generator and forward to send sensor interface, process
power change 9 APU power PowerSensor Receive On change, calculate
Locomotive reported power and engine Equipment 6 1 RPM sensor
values (synthesize) and send to send sensor interface, process
power change 10 APU APU ID APU On receipt, process Command response
Interface
[0079] In TABLE 3, Line 1 indicates that engine RPM instructions
are present on Receive Engine Interface 1, which refers to the
intercepted engine RPM control instruction from the legacy
locomotive controller 162. The action(s) that the intercept
locomotive controller 162 takes in response to this instruction
are: (1) calculate the power request, and (2) allocate power
requests to the locomotive consist 110. These actions are described
in additional detail elsewhere herein.
[0080] Line 2 of TABLE 3 indicates that generator excitement
instructions will be present on Receive Engine Interface 2. These
generator excitement instructions are the intercepted generator
excitement voltage from the legacy locomotive controller 114. The
action(s) that the intercept locomotive controller 162 takes in
response to these instructions are: (1) calculate the power
request, and (2) allocate power requests to the locomotive consist
110. These actions are described in additional detail elsewhere
herein.
[0081] In an exemplary embodiment, the above-referenced RPM
instructions and generator excitement instructions are received in
the Cummins6500 format, however, one skilled in the art will
recognize that the instructions may be received in alternative
formats.
[0082] Line 3 of TABLE 3 indicates an exemplary connection by the
intercept locomotive controller 162 to pre-existing fault circuitry
within the locomotive 112 using the Receive Locomotive Equipment 0
interface. In this exemplary connection, the fault sensor is tied
to the MU interface fault line and uses the MU signaling standard,
however, embodiments of the invention are equally applicable to
alternative signaling standards. The intercept locomotive
controller 162 is configured to periodically poll the interface,
register a change in voltage on this interface as a fault, process
that fault, and forward the fault indication to other locomotive
systems on send sensor interface 170.
[0083] Line 4 of TABLE 3 indicates an exemplary intercept by the
intercept locomotive controller 162 of a traction motor temperature
sensor on the Receive Locomotive equipment 1 interface. The
traction motor temperature sensor is configured as reporting using
a known temperature sensor reporting mechanism (shown as the
control-reporting model "TempSensor"). The intercept locomotive
controller 162 is configured to poll this interface periodically,
and report changes by echoing them to the legacy locomotive
controller 162 on a send sensor interface 170.
[0084] Line 5 of TABLE 3 indicates an exemplary intercept by the
intercept locomotive controller 162 of a traction motor power draw
sensor on a Receive Locomotive Equipment 2 interface. The power
draw sensor reports power using a known power reporting mechanism
(shown as the control-reporting model "PowerSensor"). The intercept
locomotive controller 162 is configured to detect a change in the
reported value, recalculate the amount of reported power in
accordance with the amount of power the legacy locomotive
controller 114 is expecting to see on the bus 124, and send the
calculated amount of reported power encoded using the "PowerSensor"
scheme to the legacy locomotive controller 114 on a send sensor
interface 170.
[0085] Note that in this exemplary embodiment the intercept
locomotive controller 162 is passively managing the traction motor
draw and temperature in order to cause the legacy locomotive
controller 114 to properly manage cooling of the traction motor
128. In other embodiments, the intercept locomotive controller 162
may be configured to receive a traction motor temperature and/or a
traction motor power draw value, calculate the amount of cooling
required, and directly control the traction motor 128 and/or
traction motor blower 204. This illustrates the flexibility of the
intercept approach to managing a legacy locomotive.
[0086] Line 6 of TABLE 3 indicates an exemplary intercept of the DC
bus power sensor 140 by the intercept locomotive controller 162 on
the Receive Locomotive Equipment 3 interface. The DC bus power
sensor 140 reports power using a known power reporting mechanism,
referred to herein as the control-reporting model "PowerSensor".
The intercept locomotive controller 162 is configured to detect a
change in the reported value, recalculate the amount of power
available to the locomotive 112 using previous power requests from
the legacy locomotive controller 114, and transmit the recalculated
sensor value to the legacy locomotive controller 114 on send sensor
interface 170. Note that the amount of power reported to the legacy
locomotive controller 114 may be replaced, scaled, or similarly
adjusted to provide "expected" values of DC bus power to the legacy
locomotive controller 114.
[0087] Line 7 of TABLE 3 indicates an exemplary intercept of the
first engine RPM sensor by the intercept locomotive controller 162
on a Receive Locomotive Equipment 4 interface. As one non-limiting
example, the signals from the first engine RPM sensor may be
encoded using a known Engine RPM encoding scheme, such as, for
example, a Cummins encoding scheme. The intercept locomotive
controller 162 is configured to receive a changed value on this
Receive Locomotive Equipment 4 interface, adjust the reported value
to report the expected engine RPMs in accordance with a previously
requested engine RPMs and the amount of power received from other
sources (e.g., APUs 50), and to forward the calculated RPMs value
to the legacy locomotive controller 114 using a send sensor
interface 170. The intercept locomotive controller 162 then
processes a change in power provided by the engine/generator set
116 as described herein.
[0088] Line 8 of TABLE 3 indicates an exemplary intercept of the
first generator excitement sensor by the intercept locomotive
controller 162 on a Receive Locomotive Equipment 5 interface. As
one non-limiting example, the signals from the first generator
excitement sensor may be encoded using a known generator excitement
voltage scheme, such as, for example, a Cummins encoding scheme.
The intercept locomotive controller 162 is configured to receive a
changed value on this Receive Locomotive Equipment 5 interface,
adjust the value received to a value expected based upon the
requested power/excitement of the generator, and forward this
synthesized value to the legacy locomotive controller 114 on a send
sensor interface 170. The intercept locomotive controller 162 then
processes a change in power provided by the engine/generator set
116 as described herein.
[0089] Line 9 of TABLE 3 indicates an exemplary intercept of an
optional APU power sensor by the intercept locomotive controller
162 on a Receive Locomotive Equipment 6 interface. The APU power
sensor reports power using a known power reporting mechanism,
referred to herein as the control-reporting model "PowerSensor".
The intercept locomotive controller 162 is configured to detect a
change in the reported value, recalculate the amount of power
available to the locomotive 112 using previous power requests from
the legacy locomotive controller 114, synthesize sensor values for
other power source sensors, and to forward these synthesized sensor
value to the legacy locomotive controller 114 on a send sensor
interface 170. The intercept locomotive controller 162 then
processes a change in power provided to the locomotive 112 as
described herein.
[0090] Line 10 of TABLE 3 refers to signals transmitted over the
interface between the intercept locomotive controller 162 and an
APU 50 using an APU Identification interface standard through which
the intercept locomotive controller 162 receives identifying
information and operational information from the APU 50. Upon
receipt of a notification or status report from the APU 50, the
intercept locomotive controller 162 responds by processing the
notification/status report as described herein. Depending upon the
report, it may synthesize one or more sensor readings and output
them to one or more send sensor interfaces 170 configured for the
intercept locomotive controller 162.
[0091] According to various embodiments of the invention, an
intercept locomotive controller, such as intercept locomotive
controller 162, may be implemented within legacy locomotive systems
in a number of ways. In one embodiment, an intercept locomotive
controller is interfaced with a pre-existing (legacy) digital
locomotive controller. The digital locomotive controller receives
digital signal inputs and produces digital signal and control
outputs that are translated into engine, generator, and other
component actions when they are received by the controlled
component. The intercept locomotive controller intercepts sensor
signals and control outputs from the digital locomotive controller
by receiving a digital signal transmitted to the digital locomotive
controller, decoding that signal, creating replacement encoded
digital signals to be transmitted to the digital locomotive
controller. In an alternative embodiment, an intercept locomotive
controller is interfaced with a pre-existing analog
electro-mechanical locomotive controller. The pre-existing analog
controller receives analog signal inputs characterized as voltages,
amperages, and/or waveforms proportional to their sensor readings
and produces analog signal and control outputs characterized by
voltages, amperages, and/or waveforms proportional to the desired
control actions that are translated into engine, generator, and
other component actions when they are received by the controlled
component. Examples of these waveforms include amplitude
modulation, frequency modulation, and hybrid schemes such as
pulse-width-modulation (PWM). The intercept locomotive controller
intercepts the sensor signals and control outputs by receiving an
analog signal, decoding that signal and translating it so it may be
acted upon by the intercept locomotive controller, and then
creating replacement analog signals reflecting the control intent
of the intercept locomotive controller. In yet another alternative
embodiment, the intercept locomotive controller is interfaced to a
pre-existing (legacy) analog or digital "genset" locomotive
controller. Genset controllers differ from a traditional locomotive
controller in that they support more than one engine/generator
set.
[0092] In each of the above-described implementations, the
intercept locomotive controller 162 is electrically connected
between the control outputs of the legacy locomotive controller 114
and the engine/generator set 116 of the legacy locomotive 112. The
intercept locomotive controller 162 receives control signals from
the legacy locomotive controller 114, receives inputs from external
power sources or APUs 50, and inputs from sensors attached to the
traction bus 124 and/or traction motors 128. Optionally, the
intercept locomotive controller 162 may also be interconnected so
as to receive other inputs, such as inputs from generator-based
sensors 122. The intercept locomotive controller 162 uses these
inputs to determine the desired control adjustments, determines the
attributes of modified control and sensor signals, and then
transmits modified control signals to the engine/generator set 116
in order to configure the amount of power generated by the legacy
locomotive engine/generator set 116.
[0093] Optionally, the intercept locomotive controller 162 also
transmits control signals to an APU 50 (and APU controller 70) via
control cables 100 in order to set or control the amount of power
generated by the APU 50. Intercept locomotive controller 162 is
also programmed to generate a traction motor command that is
configured to maintain desired or requested levels of tractive
power to the traction motors 128 consistent with the (implied
intent) of the original control signal from the legacy locomotive
controller 114. The intercept locomotive controller 162 may also
modify or generate other signals that are passed to the legacy
locomotive controller 114 in order cause the legacy locomotive
controller 114 to behave as if it were connected directly to the
engine/generator set 116 without the intercept locomotive
controller 162 or the external power provided by the APU 50. The
power produced by APU 50 is then transmitted to locomotive traction
bus 124 via power cables 142.
[0094] In the case of a fault of a locomotive engine/generator 118,
120, the fault may be reported by the intercept locomotive
controller 162 to the user interface 136, and/or the legacy
locomotive controller 114. In some implementations, the fault is
reported only to the user interface 136, and the power allocation
function of the intercept locomotive controller 162 requests
additional power from other engines 118 and/or APUs 50 to make up
for the loss of power from the fault. In this case, the intercept
locomotive controller 162 will report that the engine 118 in
running normally (RPM, power produced, power on the bus) when it
has actually failed. If additional power is obtained from other
locomotive equipment engines 118 (for example, by raising their
engine RPMs), their sensor values are similarly adjusted to report
that they are operating as previously instructed.
[0095] According to one embodiment, at least one of APU controller
70 and at least one of legacy locomotive controller 114 and
intercept locomotive controller 162 are configured to detect a
fault in the transmission of power and/or control commands through
control cables 100. In some embodiments, upon detection of the
fault, intercept locomotive controller 162 may forward the fault
indication to legacy locomotive controller 114. The intercept
locomotive controller 162 may be configured take one or more
actions in response to the fault condition. If the fault condition
is in the control cable connection 100 between a locomotive
controller (either 114, 162, or both) and APU 50, example actions
may include: resend one or more the power and/or control commands
to APU 50, send a status command to APU 50, read one or more
sensors and make a determination of the seriousness of the fault
condition, alert the locomotive operator thru a display or alerting
device (e.g., light, alarm signal), forward the fault to another
locomotive controller. Other actions may be programmed into the
intercept locomotive controller 162 in response to communications
faults between intercept locomotive controller 162 and APU 50 as
would be understood by those skilled in the art. Alternatively, or
in addition thereto, intercept locomotive controller 162 may be
programmed to modify a previously sent power command upon detection
of the fault, or to set APU 50 to an "unavailable" status and
reallocate power requirements allocated to APU 50 to other
engine/generator sets within the locomotive consist 110. For
example, if APU 50 is showing a connection fault on its command
circuit and it is not providing power to the power bus 124 as
indicated by power bus sensors 140, intercept locomotive controller
162 may decide that APU 50 is no longer functioning and reallocate
the power requirements allocated to APU 50 to a primary locomotive
engine/generator set 116, causing it to increase its RPMs and
alternator excitement voltages in order to provide the missing
power to the power bus 124.
[0096] In some implementations, the intercept locomotive controller
162 may report an APU 50 as an additional (phantom) primary
engine/generator combination, and interpret legacy controller power
control information to that "phantom" engine/generator as
instructions to the APU 50. In these cases, the intercept
locomotive controller 162 serves as a protocol converter that
converts engine/generator control information to/from the command
protocol of the APU 50. In addition, the intercept locomotive
controller 162 may handle APU disconnects (or simply an unconnected
APU) by reporting that the engine has been derated, has failed, or
that it has failed to respond to the control inputs.
[0097] In some instances, intercept locomotive controller 162 is
expecting a response from APU controller 70 that is not received,
or is receiving in an unusable form. In this case, intercept
locomotive controller 162 may take one or more actions to respond
to the missing response. For example, these actions may include any
or all of the following: resend one or more the power and/or
control commands to APU 50; send a status command to APU 50; read
one or more sensors and make a determination of the seriousness of
the fault condition; alert the locomotive operator using a display
or alerting device (e.g., light, alarm signal), generate a fault to
another locomotive controller, generate a fault on one or more
interfaces (such as the MU interface). Other actions may be
programmed into intercept locomotive controller 162 in response to
communications faults between intercept locomotive controller 162
and APU 50 as would be understood by those skilled in the art.
[0098] In other instances, intercept locomotive controller 162 may
receive notifications from APU controller 70 asynchronously. These
notifications may comprise event or alert notifications, or may
simply comprise information provided by APU controller 70 that
intercept locomotive controller 162 may consider in managing
locomotive consist 110. The actions taken by intercept locomotive
controller 162 in response to these notifications may include any
or all of the following: do nothing, send a command to APU
controller 70 requesting additional information about APU
controller memories 98; process the received information as a fault
indication or as a connection notification; process the received
information as a sensor reading related to APU operation; store the
received information in intercept locomotive controller memory 146
for use during power cost calculations; store the received
information in locomotive controller memory 146 for use in
subsequent power allocation calculations; recalculate the cost of
power provided by APU 50 for use in power allocation decisions;
reallocate power allocation to APU 50; and command APU 50 to
provide a differing amount of power to locomotive power bus 124.
Other actions may be programmed into intercept locomotive
controller 162 in response to notifications received by intercept
locomotive controller 162 from APU 50 as would be understood by
those skilled in the art.
[0099] Intercept locomotive controller 162 may recognize that
something is connected to its control line based upon the presence
or absence of voltage, current or capacitance on the line. Upon
recognizing the connection of a new device to the locomotive
control line (and the connection of the power and control circuits
or cables), intercept locomotive controller 162 undertakes the
following steps to determine information about APU 50: A)
communicate with the device to determine if indicated connection
was to an APU, a fuel assembly, or some other device, and if the
device is not an APU or fuel assembly, intercept locomotive
controller 162 takes an action consistent with a fault handling (as
described above); B) intercept locomotive controller 162 sends a
command to the device to determine device identifying information
and receives a response, and if a response is not received, it is
handled as described above; C) intercept locomotive controller 162
optionally sends additional commands to the device and receives
additional responses from the device to determine additional
information about the device, or looks up information about the
device, either in a local memory or from a remote computer, to
determine the additional information, D) intercept locomotive
controller 162 stores the information received in memory 146 for
subsequent use; and E) based upon the type of device connected,
intercept locomotive controller 162 takes additional actions
selected from the set of actions: perform power cost calculations,
perform power allocation, send a power command to APU 50, and
select a fuel assembly.
[0100] Intercept locomotive controller 162 performs power cost
calculations as the cost of providing power changes. In an
embodiment, the power cost calculation is a scalar value provided
by an external device, a calculation based upon the cost of fuel
and a conversion factor indicative of the power source's efficiency
of converting a unit of fuel into power (e.g., kilowatts per
gallon). The calculations can also utilize the energy content of
fuel provided. In some embodiments, the calculations produce a
scalar value. In others, the calculations produce an n-dimensional
based upon one or more engine performance metrics (e.g., amount of
power produced, engine RPM, generator excitement voltages, one or
more metrics related to the fuel being used (price of fuel, energy
content of fuel), and one or more metrics related to operating
conditions (e.g., temperature, air pressure). The results of these
calculations are stored in intercept locomotive controller memory
146 for further use.
[0101] Intercept locomotive controller 162 sends a power command to
APU controller 70 instructing it to provide a specific amount of
power to the power bus 124. Optionally, this power command may
include an indication that the power command should be performed
quickly, such as when intercept locomotive controller 162 is
processing wheel slip or faults. The power command send to APU
controller 70 typically differs from normal engine control voltages
in that it specifies an amount of power (current and voltage) to
provide because intercept locomotive controller 162 is generally
unaware of the power source settings associated with providing a
desired amount of tractive power. Because intercept locomotive
controller 162 is unaware of these settings, intercept locomotive
controller 162 can interoperate with APUs 50 using differing power
sources. This provides a significant operational advantage.
[0102] After intercept locomotive controller 162 sends a power
command to APU controller 70, APU controller 70 responds to
intercept locomotive controller 162 in several ways. First, APU
controller 70 responds to the power command with a response on the
control cable connection 100 to the requesting intercept locomotive
controller 162. If intercept locomotive controller 162 does not
receive the response within a configuration determined timeframe,
intercept locomotive controller 162 takes corrective action as
described above for missed response. Secondly, intercept locomotive
controller 162 monitors sensors 140 on power bus 124 to determine
if APU 50 as provided the requested power. If the power requested
does not appear on power bus 124 within a configuration determined,
or dynamically determined timeframe, intercept locomotive
controller 162 handles this failure to respond as a fault (as
described above).
[0103] One aspect of intercept locomotive controller 162 is to
manage locomotive consist 110 with respect to overall emissions
produced. APUs 50 may provide to intercept locomotive controller
162 information (graphs or scalar metrics) that represent the
emissions produced or with respect to emissions produced by each
engine. In order to obtain emissions levels which adhere within
certain limits or which better match certain target objectives,
intercept locomotive controller 162 may determine that APU 50
should operate using a certain balance of one fuel in preference to
another (e.g., natural gas as opposed to syngas), or to use a
certain mix of the two fuels over a particular time scale. For
instance, a locomotive consist may not be able to achieve desired
management of both NOx and particulate matter emissions over a
certain distance or time by running natural gas 100% of the time.
Intercept locomotive controller 162 makes this determination based
upon higher level calculations based in part upon the emissions
profile of the power sources available to intercept locomotive
controller 162, their emissions profile under particular load
conditions, fuels available, and the location of locomotive consist
110 and its projected load conditions. Intercept locomotive
controller 162, when making these calculations, adds the steps of
sending a request to one more of the APU 50, fuel assemblies 52 to
determine the fuel types and emissions profiles for power requests
to APU 50. Intercept locomotive controller 162 receives the
requested information, stores it in memory 146, and then uses
processor 116 to calculate the emissions profiles. Once the
emissions profiles are calculated, intercept locomotive controller
162 makes a determination regarding fuels to use and power
allocations, and instructs APU 50 and/or fuel assemblies 52
appropriately.
[0104] In some implementations, the intercept locomotive controller
162 is programmed with the legacy locomotive controller type,
sensor types and interface connections (and expected ranges),
engine/generator types/control parameters and interface
connections, and similar information. This information may be
programmed in when the intercept locomotive controller 162 is
installed, or it may be preprogrammed into the controller itself.
Optionally, the intercept locomotive controller 162 may interrogate
attached devices to determine the information required. In some
implementations, the intercept locomotive controller 162 may
observe the control signals and/or presented by portions of the
locomotive control system 113 and determine the appropriate
settings by looking up observed information in an internal database
of observed settings. The auxiliary power enabled locomotive
control system 113, including a legacy locomotive controller 114
and an intercept locomotive controller 162, is able to make power
allocations between power sources. The auxiliary power enabled
intercept locomotive controller 162 specifically is able to
determine if an APU 50 is connected, and if so, use APU 50 as one
of the available power sources by integrating the operations of the
APU 50 into the locomotive operations by intercepting control
information and sensor inputs and creating synthesized control
information.
[0105] Intercept locomotive controller 162 is coupled to a memory
module 146 within which is stored its current cost of producing
power using the standard power. The current costs of producing
power may be a unique number, or may be a sequence of numbers
stored in a look-up table based upon engine RPM. In one embodiment,
memory module 146 also stores a price of fuel for locomotive
engines 78. This price can be manually or electronically updated on
a periodic basis. Intercept locomotive controller 162, using this
table, and the known engine RPMS, can compute the cost of providing
a unit of power to the locomotive's traction and/or auxiliary power
busses 124, 126. This cost is called the internal generation
cost.
[0106] Knowing the current cost of power, intercept locomotive
controller 162 may then seek lower cost power from APU 50 when APU
50 is able to provide power for the locomotive busses 124, 126 at
costs below the internal generation cost. Intercept locomotive
controller 162 reads the current power cost from APU controller 70,
and compares the internal generation cost to the price provided by
APU controller 70, and selects engine control points (and
engine/generator settings) and APU power settings to obtain power
from at least one of the lowest cost source and a combination of
sources whose costs aggregate to the lowest total cost. In some
cases, this means intercept locomotive controller 162 will power
down the engine/generator sets 116 and use only power produced by
APU 50. In other cases, intercept locomotive controller 162 will
use power generated by both APU 50 and engine/generator sets 116.
In still other cases, intercept locomotive controller 162 will idle
APU 50 and use only onboard power produced by engine-generator sets
116.
[0107] In one embodiment, the power command transmitted by
intercept locomotive controller 162 will specify a desired amount
of power. In other embodiments, the power command transmitted by
intercept locomotive controller 162 may specify a desired operating
point on a performance graph of APU 50 or a desired power level of
the output power of APU 50.
[0108] In an optimization to this algorithm, railroads may purchase
bulk power from power providers using APU 50 as described above.
Their power purchases may be stored within and reported by a meter
(not shown) provided within in APU 50. Intercept locomotive
controller 162 may interrogate the meter and determine the amount
of power remaining in the current bulk purchase, and make its power
allocation decisions based at least in part upon the amount of
power previously purchased. This is especially advantageous when
the bulk purchases are "use or lose", and it is advantageous to the
locomotive operator to use all of their previously purchased power.
Depending upon the embodiment, the optimization algorithm can also
include the aspect that with APU 50 operating, the overall power
available to the traction bus 124 can be higher than with the
locomotive(s) alone, and there may be portions of the route where
the higher power has value to the railroad and therefore it is
beneficial for the system to reserve sufficient fuel for those
portions of the route. As such, the algorithm is looking at several
time periods to optimize the value of APU operation, not simply as
the minimum cost of power now.
[0109] Once operational conditions are processed, intercept
locomotive controller 162 checks for messages from APUs 50 or fuel
assemblies 52 that have not been processed. These messages are
processed, and stored information (e.g., ID information,
operational information, etc.) about the power sources and/or fuel
assemblies are updated periodically. These messages may indicate a
change in a removably connected power source 50 and/or fuel
assembly 52, fuel state or type, the amount of power provided by an
auxiliary power source, a cost of power provided, an updated graph,
or other change that intercept locomotive controller 162 takes into
account when optimizing the performance of locomotive consist
110.
[0110] If power, fuel, or cost information is updated, intercept
locomotive controller 162 then conducts a series of interactions
with the power sources and fuel assemblies to update its stored
information to current values. Intercept locomotive controller 162
then recalculates any information it has stored based upon the
updated stored values.
[0111] After completing the update of the stored information,
intercept locomotive controller 162 determines information that
will be used to support the power allocation process. This
information includes the real-time amount of power desired by the
locomotive (based upon throttle notch settings, auxiliary loads,
traction motor requirements, etc.), and determines the current
amount of power available by totaling the amount of power each
power source may provide. It further determines the power cost for
each power source, either as a scalar metric or as an efficiency
graph that describes the power costs relative to the amount of
power provided, or as a metric or efficiency graph based upon the
fuel type/composition. In some cases, fuel cost, operational
metrics such as temperature or air pressure, and other metrics are
used as inputs in determining the power cost. Other parameters such
as power sources requested to produce a minimum amount of power are
also collected. In an embodiment, this information may include
emissions and or maintenance schedule information about each of the
power sources.
[0112] Intercept locomotive controller 162 then checks to determine
if the power provided to locomotive 112 is within a configuration
specified tolerance of the power requested to operate the
locomotive 112. If the power requested and power provided are out
of tolerance, or one of the power cost parameters changed,
intercept locomotive controller 162 makes a power allocation
between the power sources, dividing the locomotive power
requirement between available power sources, such as, for example,
locomotive engine-generator sets 116 and auxiliary power sources
such as APU 50. In one embodiment, the power allocation is
performed in a way to minimize the total cost of power utilized by
the locomotive 112, using the power cost and minimum/maximum
amounts of power produced for each power source as input. In some
embodiments, the power cost is a graph that represents the varying
power cost based upon the amount of power provided. Intercept
locomotive controller 162 finds the minimum total cost based upon
the amount of power requested, and sets the primary power sources
(e.g., sets excitement and RPMs of generator 120) and sends
requests to APUs 50 to provide the desired amount of power.
[0113] Power allocation algorithms may be very complex, and may
include current location, anticipated power requirements, and other
factors in the allocation algorithm. In some embodiments, the power
allocation may be simplified to use fuel costs as the allocation
factor. For example, when the difference between diesel and natural
gas fuel prices exceed a certain level, the lower priced fuel is
always less expensive to operate. Similarly, if specific fuels are
available, it may more efficient to operate with those fuels. The
results of the power allocation process are stored in intercept
locomotive controller memory 146 for subsequent use.
[0114] Intercept locomotive controller 162, having configured
locomotive consist 110 to operate with a specific source and
amounts of power then monitors the power provided by each power
source to determine if the amount of power being provided is in
accordance with the settings, and makes adjustments to the power
source configurations as needed to keep the amount of power
provided to the locomotive in line with the power requirements. The
control loop then repeats on a periodic interval.
[0115] In applications where fuel assemblies 52 have direct control
and fuel connections 148, 150 with locomotive 112, valves (not
shown) fluidly connect pressure tanks 60 to locomotive engines 118.
Intercept locomotive controller 162 may interrogate each fuel
assembly 52, determine the type of fuel, its cost, and its energy
density, and determine which of the available fuels it should use
in the current situation based on the information received from
fuel assemblies 52. After selecting the fuel to use, intercept
locomotive controller 162 can configure the engine operating
parameters (idle, timing, etc.) so engines 78 process the selected
fuel most efficiently. For example, it may be cost effective to use
syngas or process gas while engines 78 are idling, and to use LPG
when the engines 78 are running at maximum RPM. Similarly,
intercept locomotive controller 162 can use fuel cost and/or fuel
energy density as inputs in determining which fuel should be used
in the current situation.
[0116] In an embodiment that blends power from an APU 50 and the
locomotive engine 118, the amount of power delivered to the
traction motors 128 is the sum of the APU power and the locomotive
diesel power. In some instances, the APU sourced power will
comprise the large majority of power delivered to the traction
motors 128. The challenge is to provide sufficient traction motor
cooling air when the locomotive 112 is now generally putting out
considerably less tractive bus electrical power. For example, while
the locomotive engine 118 is no longer operated at high RPM for the
purpose of producing tractive power, lowering the RPM of engine 118
may reduce the amount cooling air provide to the traction motors to
a level below that appropriate for the level of power flowing on
the traction bus 124. As previously described, each of the extant
drive methods depends either directly (mechanical drive, first
electric drive method) or indirectly (second electric drive method
in its available power limitations) on the diesel RPM to provide
adequate cooling airflow from traction motor blowers 204 to the
traction motors 128. An example operating plan for intercept
locomotive controller 162 that maintains the RPM of
engine-generator set 116 is detailed above in TABLE 1.
[0117] Described herein are various approaches to providing
adequate traction motor cooling when a legacy locomotive 112 is
operating with an APU 50. In a fast idle embodiment (exemplified
above by operating plan in TABLE 2), the existing traction motor
blowers 204 are used and the intercept locomotive controller 162
transmits a blower motor command that permits locomotive diesel
engine 118 to run at the specific RPM associated with each notch,
but can run with a lower load and therefore lower fuel consumption
and emissions. Note the load on the diesel engine 118 can be
modulated by controlling the excitation of the main and/or
companion alternator 120 of the locomotive 112.
[0118] The traction motor blowers 204 may be controlled using an
electric drive from the existing locomotive power train, a
mechanical drive from existing locomotive power train (i.e., power
take off from the diesel engine 118), or a hydraulic drive of the
traction motor blowers 204, effected by power take off from the
diesel engine 118 to drive a hydraulic pump, connected
hydraulically to hydraulic motor driving traction motor blower 204,
with appropriate valves, accumulators, and pressure regulators in
hydraulic lines.
[0119] In electric drive embodiments, control of the traction motor
blowers 204 may be effected via AC directly from the main
generator, AC directly from an companion alternator, AC directly
from an auxiliary generator, or a combination thereof with added
VFD. Alternatively, control may be effected by inverting DC power
from the power bus 124 to drive traction motor blowers 204, or
driving AC or DC traction motor blowers 204 using electric energy
stored in batteries on the locomotive 112 or a tender.
[0120] In mechanical drive embodiments where the legacy locomotive
112 includes a mechanical drive for the traction motor blowers 204,
the mechanical drive may be left as is, or a gearbox or
transmission may be incorporated to provide either a fixed ratio
speed increase or variable speed for operation of traction motor
blowers 204. Alternatively or in addition thereto, a clutch may be
included in the mechanical drive train of fraction motor blowers
204 to permit complete/rapid periodic/partial depowering of
traction motor blowers 204 when, for example, "fixed" engagement of
power train would provide for an excess of blower air according to
the momentary cooling appropriate for the traction motors 128.
[0121] In alternative embodiments, the existing traction motor
blowers 204 may be used at a slow diesel RPM/no fast idle
condition. In such embodiments, the locomotive diesel RPM and power
output is controlled to produce enough power, when summed with the
power produced by one or more power sources on one or more
auxiliary power unit assemblies 48, to be adequate to supply the
amount of power associated with the specific notch requested by the
train crew, including service of locomotive hotel loads including
traction motor blowers. In such embodiments, traction motor blowers
204 may be controlled using an electric drive from the existing
locomotive power train, a mechanical drive from existing locomotive
power train (i.e., power take off from diesel), or a hydraulic
drive of the traction motor blowers, in a similar manner as
described above.
[0122] In yet another embodiment, a new source of power may be
provided for traction motor blowers 204 such as, for example, an
engine smaller than the primary engine 118, a fuel cell, or a
battery bank. Alternatively, the new source of power may include,
for example, a new "auxiliary" prime mover, an electric drive if
new auxiliary is a genset or fuel cell, including all AC or DC
variants of driving traction motor blowers, a mechanical drive from
new auxiliary prime mover shaft power, a battery bank, and transfer
of AC or DC power from an APU 50 not on the locomotive chassis. The
sole or shared purpose of this new power source would be to power
traction motor blowers 204.
[0123] New traction motor blowers may also be provided. Such
traction motor blowers may either supplement existing fraction
motor blowers and pneumatically connect in parallel or series with
extant traction motor blowers, or replace existing traction motor
blowers with new ones sized to yield adequate airflow at low
locomotive diesel RPM, either with "excess" airflow at higher RPM
or with modulated flow to reduce "excess" airflow at higher
RPM.
[0124] A refrigeration system may also be included to provide
pre-cooled air supply to cool traction motors 128, thus providing
adequate cooling under either "fast idle" air flow regimes or
"slow/no fast-idle" air flow regimes.
[0125] An air storage system may also be provided on locomotive 112
for purpose of accumulating compressed air volumes to be released
as supplement to e.g., "slow/no fast idle" traction motor blower
air flow. A reservoir for such system could be integral to
locomotive chassis or on separate car chassis. The reservoir could
be "pre-charged" before train starts trip and/or replenished by
compressor mechanism during train operations.
[0126] FIG. 5 illustrates an exemplary control process 220
implemented by an intercept locomotive controller, such as
intercept locomotive controller 162 described with respect to FIGS.
2-4. This control process 220 may be performed asynchronously when
a control input changes, or upon a regularly scheduled, or
calculated, repeating basis. At step 222, the intercept locomotive
controller 162 receives control and sensor inputs from one or more
of the legacy locomotive controller 114, engine/generator sensors
122, power sensors 140, and other sensors 200 provided within
locomotive 112. The intercept locomotive controller 162 transforms
these control and sensor inputs into digital values, which are
stored in a memory 164 of the intercept locomotive controller
162.
[0127] The intercept locomotive controller 162 then proceeds to
step 224 wherein a power allocation between available power sources
is determined. Using the digital values stored in the memory 146 of
intercept locomotive controller 162 during step 222, the intercept
locomotive controller 162 then looks up the resulting power and
sensor values in one or more power allocation/sensor value lookup
tables and/or other control allocation tables. The power and sensor
values are stored in memory 164 for use by subsequent steps.
[0128] In optional step 226 (shown in phantom), the intercept
locomotive controller 162 uses at least one of the values stored in
memory 164 to provide a control output to APU 50 in order to set
the amount and/or characteristics of power provided by the APU 50.
In some implementations, this step may be omitted because the APU
50 provides consistent power.
[0129] In step 228, the intercept locomotive controller 162 then
uses at least one of the values stored in memory 164 to provide a
control output to the engine/generator set 116 of locomotive 112 in
order to set the amount and/or characteristics of power provided by
the engine/generator set 116. The process proceeds to step 230,
where the intercept locomotive controller 162 then uses at least
one of the values stored in memory 164 to provide sensor data to
the legacy locomotive controller 162.
[0130] One of the aspects of the intercept locomotive controller
162 is that it permits the allocation of required power on the
traction bus 124 to one or more locomotive engine/generator sets
116 and/or external power units or APUs 50, without changing the
existing legacy locomotive control system and engine/generator
configuration. This permits the existing legacy locomotive 112 to
operate within its existing emissions certifications.
[0131] A second aspect of the intercept locomotive controller 162
is that it permits the allocation of requested locomotive power
based upon the availability of lower cost power. In a simple
implementation, the allocation may be predetermined and encoded
within the memory 164 of the intercept locomotive controller 162.
For example, if the external power unit or APU 50 has a cost per
unit power that is significantly below the cost of running the
legacy locomotive engine/generator set 116, the intercept
locomotive controller 162 may make a power allocation decision to
allocate a majority of the power demand to the APU(s) 50. This
allocation may range from 50% to 100%, depending upon the relative
cost of power and restrictions to keep the legacy locomotive
engine/generator set 116 operating in order to provide auxiliary
power or for regulatory reasons. Should regulatory restrictions
permit or require a different allocation range, the intercept
locomotive controller 162 can be re-configured to allocate power
requests accordingly.
[0132] A third aspect of the intercept locomotive controller 162 is
that it permits operation with external, auxiliary power units over
which there is no effective control. When this situation occurs,
the intercept locomotive controller 162 has received inputs from
the legacy locomotive controller 114 and from a sensor monitoring
the power available on the traction bus 124 or of the draw of one
or more traction motors 128. Based upon the amount of power
available and/or the power used and the encoded locomotive power
setting command inputs from the legacy locomotive controller 114,
the intercept locomotive controller 162 determines at least one
control setting for the legacy locomotive engine/generator 118, 120
and creates a control signal effective to control the production of
tractive power by the legacy locomotive engine/generator set
116.
[0133] A fourth aspect of the intercept locomotive controller 162
is that it permits legacy locomotives to operate in conjunction
with alternative fuel-based power, such as gaseous fuels, without
modifying the existing legacy locomotive controller. Use of such
fuels can require additional modifications to a legacy locomotive
or the use of APUs 50 capable of using such fuels. Embodiments of
the described systems and methods also support the concept of power
arbitrage between differently fueled locomotive power sources,
where the arbitrage is made based upon cost of fuel or the cost of
delivered power vs. the power requests of locomotive traction and
auxiliary loads.
[0134] A fifth aspect of the intercept locomotive controller 162 is
that it supports the use of auxiliary power unit assembly
arrangements in order to permit the provision of additional power
to a locomotive over the amount of power that can be produced by
the engine/generator combination(s) that are part of the diesel
locomotive. In some operational situations, such as when the
locomotive consist is running at higher speeds, the pulling
capacity of the locomotive is limited by the amount of power that
can be provided by the locomotives to their traction motors. The
use of auxiliary power permits the locomotive to move the train to
greater speeds.
[0135] Still further, embodiments of the described systems and
methods enable a metering-based power delivery approach, where the
locomotive power use from alternative fuel power sources is metered
and may be separately invoiced or billed to the railroad or
locomotive operator. While the systems and methods of use set forth
herein are described as being used in connection with the
locomotive industry, one skilled in the art will recognize that the
benefits of the fuel assembly, rail car assembly, and method for
providing fuel are equally applicable to any number of alternative
industrial applications in which a fuel tank is coupled to an
engine, such as, for example, in the trucking industry or the
maritime industry.
[0136] One key aspect when using alternative fuel types in an
auxiliary power unit assembly is the differential in fuel cost, or
ultimately, the cost of a unit of power provided to a power bus.
Embodiments of the intercept locomotive controller 162 set forth
herein are able to arbitrage fuel and power costs between the
locomotive's power sources and auxiliary power unit assemblies
provided in a power tender to more efficiently operate. Further,
the intercept locomotive controllers and auxiliary power unit
assemblies set forth herein are able to communicate additional
information (such as its ID, control input description, control
settings/emissions, control setting/generated power graphs, fuel
type, power cost) about the control and operation of the auxiliary
power unit to the intercept locomotive controller 162. Absent at
least some of this information, the intercept locomotive controller
162 would be unable to effectively control the auxiliary power
units.
[0137] Various features and aspects of the above described system
may be used individually or jointly. Further, although embodiments
of the intercept locomotive controller have been described in the
context of its implementation in a particular environment, and for
particular applications (e.g., railroad usage), those skilled in
the art will recognize that its usefulness is not limited thereto
and that the system can be beneficially utilized in any number of
environments and implementations where it is desirable to retrofit
existing power generator controllers in order to use external power
units or to arbitrage power costs from alternative fuel generation
sources.
[0138] More generally, from the foregoing, it will be appreciated
that specific embodiments of the technology have been described
herein for purposes of illustration, but that various modifications
may be made without deviating from the technology. Certain aspects
of the technology described in the context of particular
embodiments may be combined or eliminated in other embodiments.
Further, while advantages associated with certain embodiments of
the technology have been described in the context of those
embodiments, other embodiments may also exhibit such advantages,
and not all embodiments need necessarily exhibit such advantages to
fall within the scope of the present technology. Accordingly, the
disclosure and associated technology can encompass other
embodiments not expressly shown or described herein.
[0139] A technical contribution for the disclosed method and
apparatus is that it provides for a computer implemented control of
an intercept locomotive controller that is electrically coupled
between a locomotive controller and a primary power unit of the
locomotive and that is programmed to intercept an initial
locomotive control signal transmitted from the legacy locomotive
controller to the primary power unit indicating an amount of
locomotive power, modify the initial locomotive control signal, and
transmit the modified control signal to the primary power unit.
[0140] One skilled in the art will appreciate that embodiments of
the invention may be interfaced to and controlled by a computer
readable storage medium having stored thereon a computer program.
The computer readable storage medium includes a plurality of
components such as one or more of electronic components, hardware
components, and/or computer software components. These components
may include one or more computer readable storage media that
generally stores instructions such as software, firmware and/or
assembly language for performing one or more portions of one or
more implementations or embodiments of a sequence. These computer
readable storage media are generally non-transitory and/or
tangible. Examples of such a computer readable storage medium
include a recordable data storage medium of a computer and/or
storage device. The computer readable storage media may employ, for
example, one or more of a magnetic, electrical, optical,
biological, and/or atomic data storage medium. Further, such media
may take the form of, for example, floppy disks, magnetic tapes,
CD-ROMs, DVD-ROMs, hard disk drives, and/or electronic memory.
Other forms of non-transitory and/or tangible computer readable
storage media not list may be employed with embodiments of the
invention.
[0141] A number of such components can be combined or divided in an
implementation of a system. Further, such components may include a
set and/or series of computer instructions written in or
implemented with any of a number of programming languages, as will
be appreciated by those skilled in the art. In addition, other
forms of computer readable media such as a carrier wave may be
employed to embody a computer data signal representing a sequence
of instructions that when executed by one or more computers causes
the one or more computers to perform one or more portions of one or
more implementations or embodiments of a sequence.
[0142] Therefore, according to one embodiment of the invention, a
locomotive assembly includes a power bus, a locomotive, and an
intercept locomotive controller. The locomotive includes a primary
power unit coupled to the power bus and a legacy locomotive
controller programmed to transmit a control command to the primary
power unit. The intercept locomotive controller is electrically
coupled between the locomotive controller and the primary power
unit and is programmed to intercept an initial locomotive control
signal transmitted from the legacy locomotive controller to the
primary power unit indicating an amount of locomotive power, modify
the initial locomotive control signal, and transmit the modified
control signal to the primary power unit.
[0143] According to another embodiment of the invention, a method
of controlling a locomotive includes relaying an initial locomotive
control signal from a legacy locomotive controller designed to
control at least one power source on the locomotive to an intercept
locomotive controller, the initial locomotive control signal
comprising an encoded request for a locomotive power setting. The
method also includes determining a power output corresponding to
the locomotive power setting and allocating the power output
between the at least one power source on the locomotive and an
auxiliary power source. The method further includes transmitting a
modified locomotive control signal to the at least one power source
on the locomotive based on the power output allocation, the
modified locomotive control signal different from the initial
locomotive control signal and transmitting an auxiliary command
signal to the auxiliary power source based on the power output
allocation.
[0144] According to yet another embodiment of the invention, a
computer readable storage medium having stored thereon a computer
program comprising instructions which, when executed by at least
one processor, cause the at least one processor to receive an
initial locomotive power setting command from a locomotive
controller, the initial locomotive power setting command indicating
a desired tractive power. The instructions also cause the at least
one processor to modify the initial locomotive power setting
command and transmit the modified locomotive power setting command
to a locomotive power source. The instructions further cause the at
least one processor to receive a sensor signal corresponding to the
modified locomotive power setting command, modify the sensor signal
to match an expected sensor signal for the initial locomotive power
setting command, and transmit the expected sensor signal to the
locomotive controller.
[0145] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments.
[0146] Accordingly, the invention is not to be seen as limited by
the foregoing description. The patentable scope of the invention is
defined by the claims, and may include other examples that occur to
those skilled in the art. Such other examples are intended to be
within the scope of the claims if they have structural elements
that do not differ from the literal language of the claims, or if
they include equivalent structural elements with insubstantial
differences from the literal language of the claims.
* * * * *